




版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领
文档简介
StatisticsforBusiness
andEconomicsAndersonSweeneyWilliamsSlidesbyJohnLoucksSt.Edward’sUniversityStatisticsforBusiness
andEcChapter17
IndexNumbersPriceRelativesAggregatePriceIndexesComputinganAggregatePriceIndex fromPriceRelativesSomeImportantPriceIndexesDeflatingaSeriesbyPriceIndexesPriceIndexes:OtherConsiderationsQuantityIndexesChapter17
IndexNumbersPricePriceRelativesAbaseperiod
isagivenstartingpointintime.Apricerelativeexpressestheunitpriceineachperiodasapercentageoftheunitpriceinthebaseperiod.Apricerelativeshowshowthecurrentpriceperunitforagivenitemcomparestoabaseperiodpriceperunitforthesameitem.Pricerelativesarehelpfulinunderstandingandinterpretingchangingeconomicandbusinessconditionsovertime.PriceRelativesAbaseperiodiPriceRelativesTelevision11,469
23,904Newspaper$14,794$29,4121998
2008 ThepricesBescopaidfornewspaperandtelevisionadsin1998and2008areshownbelow.
Using1998asthebaseyear,computea2008price
indexfornewspaperandtelevisionadprices.Example:BescoProductsPriceRelativesTelevisionPriceRelativesTelevisionadvertisingcostincreasedatagreaterrate.NewspaperTelevisionPriceRelativesTelevisionadveAnaggregatepriceindex
isdevelopedforthespecificpurposeofmeasuringthecombinedchangeofagroupofitems.AggregatePriceIndexeswhere
Pit=unitpriceforitemiinperiodt
Pi
0=unitpriceforitemiinthebaseperiodAnunweightedaggregatepriceindexinperiodt, denotedbyIt
,isgivenbyAnaggregatepriceindexisdeLettingQi=quantityforitemi,theweightedaggregatepriceindexinperiodtisgivenbyAggregatePriceIndexeswherethesumsareoverallitemsinthegroupWithaweightedaggregateindex
eachiteminthegroupisweightedaccordingtoitsimportance,whichtypicallyisthequantityofusage.LettingQi=quantityforitemAggregatePriceIndexesWhentheweightsarebasedonperiodtusage,theindexisaPaascheindex.Whenthefixedquantityweightsaredeterminedfromthebase-yearusage,theindexiscalledaLaspeyresindex.AggregatePriceIndexesWhenthAggregatePriceIndexes Dataonenergyconsumption andexpendituresbysectorforthe cityofRockdalearegivenonthenextslide. Constructanaggregate priceindexforenergyexpendituresin2008 using1990asthebase
year.Example:CityofRockdaleAggregatePriceIndexes DataAggregatePriceIndexes Transport. 15,293 20,262 2.32 6.16 Industrial 21,287 17,832 .79 5.13 Commercial 5,416 6,015 1.97 11.32 Residential 9,473 8,804 $2.12 $10.92
Sector
1990
2008
1990
2008 Quantity(BTU)UnitPrice($/BTU)Example:CityofRockdaleAggregatePriceIndexes TranspUnweightedAggregatePriceIndexAggregatePriceIndexesExample:CityofRockdaleUnweightedAggregatePriceIndWeightedAggregateIndex(LaspeyresMethod)AggregatePriceIndexesThePaaschevaluebeinglessthantheLaspeyresindicatesusagehasincreasedfasterinthelower-pricedsectors.WeightedAggregateIndex(PaascheMethod)Example:CityofRockdaleWeightedAggregateIndex(LaspDinawantsanindexthatmeasuresthechangeintheoverallcostofherlawncare.Priceandquantitydataforherannuallawnexpensesarelistedonthenextslide.Example:AnnualCostofLawnCareDinaEversispleasedwithherlovelylawn,butsheisconcernabouttheincreasingcostofmaintainingit.Thecostincludesmowing,fertilizing,watering,andmore.AggregatePriceIndexesDinawantsanindexthatItemQuantity(Units)MowingLeafRemovalWatering(1000sgal.)FertilizingSprinklerRepair3234021UnitPrice($)2004200857.0056.001.8356.00109.0079.0071.002.7867.00128.00Example:AnnualCostofLawnCareAggregatePriceIndexesItemQuantityMowing32UnitPriceUnweightedwhere:
Pit=unitpriceforitemi
inperiodt
Pi
0=unitpriceforitemi
inthebaseperiodUnweightedaggregatepriceindexinperiodtis:A24%increaseinannuallawncareexpensesAggregatePriceIndexesUnweightedwhere:UnweightedaggWeightedaggregatepriceindexinperiodt
is:Weighted(FixedQuantity)where:Qi=quantityforitemiNotethatQidoesnothaveasecondsubscriptforatimeperiod.A36%increaseinannuallawncareexpensesAggregatePriceIndexesWeightedaggregatepriceindexWeighted(Base-PeriodQuantity)Avariable-quantityindexSpecialcaseofthefixedquantityindexLaspeyresIndexPaascheIndexMorewidelyusedthanthePaascheindexPro:Reflectscurrentusage;Con:Weightsrequirecontin-ualupdatingWeighted(PeriodtQuantity)AggregatePriceIndexesWeighted(Base-PeriodQuantityThe5-yearincreasesinunitpricerangedfromalowof17.4%forsprinklerrepairtoahighof51.9%forwater.AggregatePriceIndexesItemiMowingLeafRemovalWater(1000sgal.)FertilizingSprinklerRepairUnitPrice($)2004200857.0056.001.8356.00109.0079.0071.002.7867.00128.00Pi
0Pi
tPriceRelative(Pi
t/Pi
0)100138.6126.8151.9119.6117.4The5-yearincreasesinunitpItemPriceRelative(Pit/Pi
0)100MowingLeavesWaterFertilizeSprinklerBasePrice($)57.0056.001.8356.00109.00Qi138.6126.8151.9119.6117.4Pi
0Quantity3234021Weightwi
=
Pi
0QiWeightedPriceRelative(Pit/Pi
0)(100)wi1,824.0168.073.2112.0109.0252,806.4021,302.4011,119.0813,395.2012,796.60Total2,286.2311,419.68AggregatePriceIndexesThisvalueisthesameastheoneidentifiedbytheweightedaggregateindexcomputation.ItemPriceMowingBase57.00Qi13Itsbaseperiodis1982-1984withanindexof100.PublishedmonthlybytheU.S.BureauofLaborStatistics.Weightedaggregatepriceindexwithfixedweightsderivedfromausagesurvey.Basedon400itemsincludingfood,housing,clothing,transportation,andmedicalitems.PrimarymeasureofthecostoflivinginU.S.SomeImportantPriceIndexesConsumerPriceIndex(CPI)Itsbaseperiodis1982-1984wConsumerPriceIndex(CPI)Base1982-1984=100.0Note:For1982–1984that(96.5
+
99.6
+
103.9)/3
=
100.0SomeImportantPriceIndexesConsumerPriceIndex(CPI)NoteIsaweightedaverageofpricerelativesusingtheLaspeyresmethod.Includestheoutputofmanufacturing,agriculture,forestry,fishing,mining,gasandelectricity,andpublicutilities.Coversraw,manufactured,andprocessedgoodsateachlevelofprocessing.Usedasaleadingindicator
ofthefuturetrendofconsumerpricesandthecostofliving.MeasuresthemonthlychangesinpricesinprimarymarketsintheU.S.ProducerPriceIndex(PPI)SomeImportantPriceIndexesIsaweightedaverageofpriceAnotheraverageiscomputedfor20transportationstocks,andanotherfor15utilitystocks.TheDJIAisnotexpressedasapercentageofbase-yearprices.TheDowJonesIndustrialAverage
(DJIA)
isbasedoncommonstockpricesof30industrialfirms.IndexesdesignedtoshowpricetrendsandmovementsontheNewYorkStockExchange.DowJonesAveragesSomeImportantPriceIndexesAnotheraverageiscomputedfoDowJonesIndustrialAverage(DJIA)30CompaniesAsof04/2009SomeImportantPriceIndexesDowJonesIndustrialAverage(DeflatingaSeriesbyPriceIndexesDeflatingactualhourlywagesresultsinrealwagesorthepurchasingpower
ofwages.Inordertocorrectlyinterpretbusinessactivityovertimewhenitisexpressedindollaramounts,weshouldadjustthedatafortheprice-increaseeffect.Removingtheprice-increaseeffectfromatimeseriesiscalleddeflatingtheseries.DeflatingaSeriesbyPriceIn McNeerCleaners,with46branchlocations,hashadthetotalsalesrevenuesshownonthenext slideforthelastfiveyears.Deflatethesalesrevenue
figuresonthebasisof1982-1984constantdollars.Istheincreaseinsalesdueentirelytotheprice-increaseeffect?Example:McNeerCleanersDeflatingaSeriesbyPriceIndexes McNeerCleaners,with46braExample:McNeerCleanersDeflatingaSeriesbyPriceIndexes
200811,690215.3
200710,724207.3
20069,830201.6
20059,062195.3
20048,446188.9 YearTotalSales($1000)CPIExample:McNeerCleanersDeflaAdjustingRevenueForthePrice-IncreaseEffectAfteradjusting,revenueisstillincreasingatanaveragerateof5.0%peryear.2008(11,690/215.3)(100)=5,430+5.02007 (10,724/207.3)(100)=5,173+6.12006(9,830/201.6)(100)=4,876+5.12005(9,062/195.3)(100)=4,640+3.82004(8,446/188.9)(100)=4,471YearDeflatedSales($1000)AnnualChange(%)DeflatingaSeriesbyPriceIndexesAdjustingRevenueForthePricRealSalesRevenue($1000s)20042005200620072008Arealsalesincreaseof21.45%from2004to20084500475050005250
55004250Year44714640517354304876DeflatingaSeriesbyPriceIndexesRealSalesRevenue($1000s)20Whentheclassofitemsisverylarge,arepresentativegroup(usuallynotarandomsample)mustbeused.Thegroupofitemsintheaggregateindexmustbeperiodicallyreviewedandrevisedifitisnotrepresentativeoftheclassofitemsinmind.SelectionofItemsPriceIndexes:OtherConsiderationsWhentheclassofitemsisverForexample,aCPIwitha1945baseperiodwouldbedifficultformostindividualstounderstand,duetounfamiliaritywithconditionsin1945.SelectionofaBasePeriodThebaseperiodformostindexesisadjustedperiodicallytoamorerecentperiodoftime.Asarule,thebaseperiodshouldnotbetoofarfromthecurrentperiod.TheCPI’sbaseperiodwaschangedto1982-84in1988.PriceIndexes:OtherConsiderationsForexample,aCPIwitha1945Anincreaseinanitem’squalitymayormaynotresultinapriceincrease...andadecreaseinqualitymayormaynotresultinapricedecrease.Isaproductthathasundergoneamajorqualitychangethesameproductitwas
?Abasicassumptionofapriceindexisthatpricesovertimeareidentifiedforthesameitem.QualityChangesPriceIndexes:OtherConsiderationsAnincreaseinanitem’squaliAnindexusedtomeasurechangesinquantitylevelsovertimeiscalledaquantityindex.Aweightedaggregatequantityindexiscomputedinmuchthesamewayasaweightedaggregatepriceindex.Aquantityrelativeshowshowthecurrentquantitylevelforasingleitemcomparestoabaseperiodquantitylevelforthesameitem.QuantityIndexesAnindexusedtomeasurechangExample:ApplianceMartApplianceMartreportsthe1999and2008salesforthreemajorkitchenappliancesasshownbelow.Computequantityrelativesandusethemtodevelopaweightedaggregatequantityindexfor2008.KitchenApplianceSalesPrice(1999)DishwasherRangeRefrigeratorSales(Units)199920087205409809506101110$325$450$710QuantityIndexesExample:ApplianceMartAKitchenApplianceDishwasherRangeRefrigeratorSales(Units)199920087205409809506101110QuantityRelative(950/720)100
=
131.9(610/540)100
=
113.0(1110/980)100
=
113.3QuantityIndexesKitchenDishwasherSales(Units)Unweightedwhere:Qit=quantityforitemi
inperiodt
Qi
0=quantityforitemi
inthebaseperiodUnweightedaggregatequantityindexinperiodtis:QuantityIndexesUnweightedwhere:Qit=quanWeighted(Base-PeriodPrice)where:Pi
0=priceforitemi
inthebaseperiodWeightedaggregatequantityindexinperiodtis:QuantityIndexesWeighted(Base-PeriodPrice)whWeighted(FixedPrice)Weighted(PeriodtPrice)NotethatPidoesnothaveasecondsubscriptforatimeperiod.QuantityIndexesWeighted(FixedPrice)WeightedEndofChapter17EndofChapter17StatisticsforBusiness
andEconomicsAndersonSweeneyWilliamsSlidesbyJohnLoucksSt.Edward’sUniversityStatisticsforBusiness
andEcChapter17
IndexNumbersPriceRelativesAggregatePriceIndexesComputinganAggregatePriceIndex fromPriceRelativesSomeImportantPriceIndexesDeflatingaSeriesbyPriceIndexesPriceIndexes:OtherConsiderationsQuantityIndexesChapter17
IndexNumbersPricePriceRelativesAbaseperiod
isagivenstartingpointintime.Apricerelativeexpressestheunitpriceineachperiodasapercentageoftheunitpriceinthebaseperiod.Apricerelativeshowshowthecurrentpriceperunitforagivenitemcomparestoabaseperiodpriceperunitforthesameitem.Pricerelativesarehelpfulinunderstandingandinterpretingchangingeconomicandbusinessconditionsovertime.PriceRelativesAbaseperiodiPriceRelativesTelevision11,469
23,904Newspaper$14,794$29,4121998
2008 ThepricesBescopaidfornewspaperandtelevisionadsin1998and2008areshownbelow.
Using1998asthebaseyear,computea2008price
indexfornewspaperandtelevisionadprices.Example:BescoProductsPriceRelativesTelevisionPriceRelativesTelevisionadvertisingcostincreasedatagreaterrate.NewspaperTelevisionPriceRelativesTelevisionadveAnaggregatepriceindex
isdevelopedforthespecificpurposeofmeasuringthecombinedchangeofagroupofitems.AggregatePriceIndexeswhere
Pit=unitpriceforitemiinperiodt
Pi
0=unitpriceforitemiinthebaseperiodAnunweightedaggregatepriceindexinperiodt, denotedbyIt
,isgivenbyAnaggregatepriceindexisdeLettingQi=quantityforitemi,theweightedaggregatepriceindexinperiodtisgivenbyAggregatePriceIndexeswherethesumsareoverallitemsinthegroupWithaweightedaggregateindex
eachiteminthegroupisweightedaccordingtoitsimportance,whichtypicallyisthequantityofusage.LettingQi=quantityforitemAggregatePriceIndexesWhentheweightsarebasedonperiodtusage,theindexisaPaascheindex.Whenthefixedquantityweightsaredeterminedfromthebase-yearusage,theindexiscalledaLaspeyresindex.AggregatePriceIndexesWhenthAggregatePriceIndexes Dataonenergyconsumption andexpendituresbysectorforthe cityofRockdalearegivenonthenextslide. Constructanaggregate priceindexforenergyexpendituresin2008 using1990asthebase
year.Example:CityofRockdaleAggregatePriceIndexes DataAggregatePriceIndexes Transport. 15,293 20,262 2.32 6.16 Industrial 21,287 17,832 .79 5.13 Commercial 5,416 6,015 1.97 11.32 Residential 9,473 8,804 $2.12 $10.92
Sector
1990
2008
1990
2008 Quantity(BTU)UnitPrice($/BTU)Example:CityofRockdaleAggregatePriceIndexes TranspUnweightedAggregatePriceIndexAggregatePriceIndexesExample:CityofRockdaleUnweightedAggregatePriceIndWeightedAggregateIndex(LaspeyresMethod)AggregatePriceIndexesThePaaschevaluebeinglessthantheLaspeyresindicatesusagehasincreasedfasterinthelower-pricedsectors.WeightedAggregateIndex(PaascheMethod)Example:CityofRockdaleWeightedAggregateIndex(LaspDinawantsanindexthatmeasuresthechangeintheoverallcostofherlawncare.Priceandquantitydataforherannuallawnexpensesarelistedonthenextslide.Example:AnnualCostofLawnCareDinaEversispleasedwithherlovelylawn,butsheisconcernabouttheincreasingcostofmaintainingit.Thecostincludesmowing,fertilizing,watering,andmore.AggregatePriceIndexesDinawantsanindexthatItemQuantity(Units)MowingLeafRemovalWatering(1000sgal.)FertilizingSprinklerRepair3234021UnitPrice($)2004200857.0056.001.8356.00109.0079.0071.002.7867.00128.00Example:AnnualCostofLawnCareAggregatePriceIndexesItemQuantityMowing32UnitPriceUnweightedwhere:
Pit=unitpriceforitemi
inperiodt
Pi
0=unitpriceforitemi
inthebaseperiodUnweightedaggregatepriceindexinperiodtis:A24%increaseinannuallawncareexpensesAggregatePriceIndexesUnweightedwhere:UnweightedaggWeightedaggregatepriceindexinperiodt
is:Weighted(FixedQuantity)where:Qi=quantityforitemiNotethatQidoesnothaveasecondsubscriptforatimeperiod.A36%increaseinannuallawncareexpensesAggregatePriceIndexesWeightedaggregatepriceindexWeighted(Base-PeriodQuantity)Avariable-quantityindexSpecialcaseofthefixedquantityindexLaspeyresIndexPaascheIndexMorewidelyusedthanthePaascheindexPro:Reflectscurrentusage;Con:Weightsrequirecontin-ualupdatingWeighted(PeriodtQuantity)AggregatePriceIndexesWeighted(Base-PeriodQuantityThe5-yearincreasesinunitpricerangedfromalowof17.4%forsprinklerrepairtoahighof51.9%forwater.AggregatePriceIndexesItemiMowingLeafRemovalWater(1000sgal.)FertilizingSprinklerRepairUnitPrice($)2004200857.0056.001.8356.00109.0079.0071.002.7867.00128.00Pi
0Pi
tPriceRelative(Pi
t/Pi
0)100138.6126.8151.9119.6117.4The5-yearincreasesinunitpItemPriceRelative(Pit/Pi
0)100MowingLeavesWaterFertilizeSprinklerBasePrice($)57.0056.001.8356.00109.00Qi138.6126.8151.9119.6117.4Pi
0Quantity3234021Weightwi
=
Pi
0QiWeightedPriceRelative(Pit/Pi
0)(100)wi1,824.0168.073.2112.0109.0252,806.4021,302.4011,119.0813,395.2012,796.60Total2,286.2311,419.68AggregatePriceIndexesThisvalueisthesameastheoneidentifiedbytheweightedaggregateindexcomputation.ItemPriceMowingBase57.00Qi13Itsbaseperiodis1982-1984withanindexof100.PublishedmonthlybytheU.S.BureauofLaborStatistics.Weightedaggregatepriceindexwithfixedweightsderivedfromausagesurvey.Basedon400itemsincludingfood,housing,clothing,transportation,andmedicalitems.PrimarymeasureofthecostoflivinginU.S.SomeImportantPriceIndexesConsumerPriceIndex(CPI)Itsbaseperiodis1982-1984wConsumerPriceIndex(CPI)Base1982-1984=100.0Note:For1982–1984that(96.5
+
99.6
+
103.9)/3
=
100.0SomeImportantPriceIndexesConsumerPriceIndex(CPI)NoteIsaweightedaverageofpricerelativesusingtheLaspeyresmethod.Includestheoutputofmanufacturing,agriculture,forestry,fishing,mining,gasandelectricity,andpublicutilities.Coversraw,manufactured,andprocessedgoodsateachlevelofprocessing.Usedasaleadingindicator
ofthefuturetrendofconsumerpricesandthecostofliving.MeasuresthemonthlychangesinpricesinprimarymarketsintheU.S.ProducerPriceIndex(PPI)SomeImportantPriceIndexesIsaweightedaverageofpriceAnotheraverageiscomputedfor20transportationstocks,andanotherfor15utilitystocks.TheDJIAisnotexpressedasapercentageofbase-yearprices.TheDowJonesIndustrialAverage
(DJIA)
isbasedoncommonstockpricesof30industrialfirms.IndexesdesignedtoshowpricetrendsandmovementsontheNewYorkStockExchange.DowJonesAveragesSomeImportantPriceIndexesAnotheraverageiscomputedfoDowJonesIndustrialAverage(DJIA)30CompaniesAsof04/2009SomeImportantPriceIndexesDowJonesIndustrialAverage(DeflatingaSeriesbyPriceIndexesDeflatingactualhourlywagesresultsinrealwagesorthepurchasingpower
ofwages.Inordertocorrectlyinterpretbusinessactivityovertimewhenitisexpressedindollaramounts,weshouldadjustthedatafortheprice-increaseeffect.Removingtheprice-increaseeffectfromatimeseriesiscalleddeflatingtheseries.DeflatingaSeriesbyPriceIn McNeerCleaners,with46branchlocations,hashadthetotalsalesrevenuesshownonthenext slideforthelastfiveyears.Deflatethesalesrevenue
figuresonthebasisof1982-1984constantdollars.Istheincreaseinsalesdueentirelytotheprice-increaseeffect?Example:McNeerCleanersDeflatingaSeriesbyPriceIndexes McNeerCleaners,with46braExample:McNeerCleanersDeflatingaSeriesbyPriceIndexes
200811,690215.3
200710,724207.3
20069,830201.6
20059,062195.3
20048,446188.9 YearTotalSales($1000)CPIExample:McNeerCleanersDeflaAdjustingRevenueForthePrice-IncreaseEffectAfteradjusting,revenueisstillincreasingatanaveragerateof5.0%peryear.2008(11,690/215.3)(100)=5,430+5.02007 (10,724/207.3)(100)=5,173+6.12006(9,830/201.6)(100)=4,876+5.12005(9,062/195.3)(100)=4,640+3.82004(8,446/188.9)(100)=4,471YearDeflatedSales($1000)AnnualChange(%)DeflatingaSeriesbyPriceIndexesAdjustingRevenueForthePricRealSalesRevenue($1000s)20042005200620072008Arealsalesincreaseof21.45%from2004to20084500475050005250
55004250Year44714640517354304876DeflatingaSeriesbyPriceIndexesRealSalesRevenue($1000s)20Whentheclassofitemsisverylarge,arepresentativegroup(usuallynotarandomsample)mustbeused.Thegroupofitemsintheaggregateindexmustbeperiodicallyreviewedandrevisedifitisnotrepresentativeoftheclassofitemsinmind.SelectionofItemsPriceIndexes:OtherConsiderationsWhentheclassofitemsisverForexample,aCPIwitha1945baseperiodwo
温馨提示
- 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
- 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
- 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
- 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
- 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
- 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
- 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
最新文档
- 车辆捐赠合同公益性与受赠方使用规范协议
- 股东合伙出资协议书-农业科技项目投资合作协议范本
- 股份制改革试点企业股份认购及股权激励方案协议
- 知识产权转让与独家合作开发合同
- 股东股权变更与公司合规经营服务协议
- 互联网教育平台股权激励计划与分配合同
- 民宿餐饮承包服务合同范本
- 仓储物流场地技术咨询与服务协议
- 餐饮加盟店加盟店经营风险管理与防范合同
- 城市综合体物业管理与商业运营合同
- 2025年天津出租车考试资料
- 2025年湖北省中考化学试卷真题(含答案解析)
- 《人工智能基础与应用》课件 项目1 认识人工智能
- 2025至2030中国插针机行业发展趋势分析与未来投资战略咨询研究报告
- 仪器报警分级管理制度
- 2025至2030国内灭火机器人行业市场发展深度分析及前景趋势与投资机会报告
- 2025年江西省中考历史试卷(含答案)
- 测量行业工作管理制度
- 2025至2030年中国瓦行业市场调研分析及发展规模预测报告
- 2025-2030年中国地理信息行业市场深度调研及前景趋势与投资研究报告
- BA系统对电气设备动力柜(箱)的自控接口要求
评论
0/150
提交评论