Barrons Data Analysis 1 (1)

8/9/2019 Barrons Data Analysis 1 (1)

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Data Analysis 1

On the next slide is the dot plot for a set of numbers. Oneelements is labeled X. Which of the following are truestatements?

I. X has the largest !score" in absolute #alue" of anyelement in the set.II. A boxplot will plot a point li$e X as an isolated point.III. A stem plot will show X isolated from two clusters.

A. I only. %. II only &. III only D. I and II '. IIand III.


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Data Analysis (

)uppose the correlation is negati#e. *i#en two pointsfrom the scatterplot" which of the following is possible?

I. +he ,rst point has a larger x!#alue and a smaller y!#alue than the second point.

II. +he ,rst point has a larger x!#alue and a larger y!#alue than the second pointIII. +he ,rst point has a smaller x!#alue and a larger y!#alue than the second point.

A. I only %. II only &. III only D. I and III '. I"II" and III


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Data Analysis -

+o which of the boxplots can the histogram shownbelow correspond? &hoices on next slide/


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Data Analysis 0

&onsider the three points 0"--/" "(2/" and 3"1 /.*i#en any straight line" we can calculate the sum ofthe s4uares of the three #ertical distances from thesepoints to the line. What is the smallest possible #alue

this sum can be?

A. (.0 %. 3 &. 5.3

D. -3 '. none of these #alues.


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Data Analysis

Which of the following are true statements?I. )tem plots are useful both for 4uantitati#e andcategorical data sets.II. )tem plots are e4ually useful for small and #ery large

data sets.III. )tem plots can show symmetry" gaps" clusters" andoutliers.

A. I only %. II only &. III only D. I and II '. I andIII


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Data Analysis 3

Which of the following scatter plots could ha#eresulted in the residual plot shown below? +he y!axis scales are not the same in the scatterplots as

in the residual plot./


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'. 6one of these could result in the gi#enresidual plot.


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Data Analysis 2A study is conducted relating A7 )tatistics exam scores to thetotal number of study hours for the A7 )tatistics class put in bystudents during the academic year" and the correlation is found tobe 8.3. Which of the following are true statements?

I. On the a#erage" a 08 percent increase in study time resultsin a (0 percent increase in exam score.II. )ixty percent of a student9s exam score can be explainedby the number of study hours.III. :igher exam scores tend to be associated with highernumbers of study hours.

A. I and II %. I and III &. II and III D. I" II" and III'. 6one of the abo#e gi#es the complete set of true responses.


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Data Analysis 5

*i#en this bac$!to!bac$ stem plot" which of thefollowing are true? &hoices on the next slide./


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I. +he 'mpirical ;ule applies to both sets A and%.

II. In one set the mean and median should beabout the same" while in the other the meanappears to be less than the median.III. +he ranges of the two sets are e4ual.

A. I only %. II only &. III only D. I and II'. II and III


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Data Analysis <

If ten executi#es ha#e salaries of =58"888" sixha#e salaries of =2 "888" and three ha#e salariesof = 28"888" what is the median salary?

A. =2 "888%. =23" 50(&. =22" 88

D. =58"888'. 6one of the abo#e.


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Data Analysis 18Which of the following are true statements about thecorrelation coe>cient r ?

I. A correlation of 8.- means that -8 of the points arehighly correlated.II. +he s4uare of the correlation measures the proportion

of the y!#ariance that is predictable from a $nowledge of x .III. 7erfect correlation" that is" when the points lie exactlyon a straight line" results in r @ 8.

A. I only %. II only &. III onlyD. 6one of these statements are true.'. 6one of the abo#e gi#es the complete set of trueresponses.


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Data Analysis 11

*i#en this cumulati#e plot" and using the mostcommonly accepted de,nition of outliers" whatages would be considered outliers? &hoices onnext slide./


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A. %etween (8 and (%. %etween (8 and -8&. %etween (8 and 08

D. %etween (8 and ( " or between and 38

'. %etween (8 and -8" or between 8and 38


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Data Analysis 1(

Data on ages in years/ and prices in =188/ for tencars of a speci,c model result in the regression line7rice @ ( 8 B -8 Age/. *i#en that 30 of the#ariation in price is explained by #ariation in age"

what is the #alue of the correlation coe>cient r ?

A. !8.30 %. !8.58 &. 8.30 D. 8.58

'. +here is insu>cient information to answer this4uestion.


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Data Analysis 1-

*i#en the two histograms below" which of thefollowing statements are true? )ee next slide./


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I. %oth sets ha#e the same mean.II. %oth sets ha#e the same range.III. %oth sets ha#e the same #ariance.

A. I only %. I and II &. I and IIID. I" II" and III'. 6one of the abo#e gi#es the complete set of

true responses.


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Data Analysis 10A real estate agent" wor$ing entirely on commission" wee$ly

ma$es an a#erage of =5 8 with a standard de#iation of=(38 selling property in the city and an a#erage of =1"-08with a standard de#iation of =-


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Data Analysis 1

*i#en that the median is (28 and the inter4uartilerange is (8" which of the following statements aretrue?I. 8 of the data are greater than or e4ual to(28.II. 8 of the data are between (38 and (58.III. 2 of the data are less than or e4ual to (58.

A. I only %. II only &. III onlyD. I and II '. I" II" and III


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Data Analysis 13

&onsider the following three scatterplots


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Which of the following is a true statement aboutthe correlation for the three scatterplots?

A. 6one are 8.%. One is 8" one is negati#e" and one is

positi#e.&. One is 8" and both of the others arenegati#e.D. +wo are 8" and the other is !1.

'. +wo are 8" and the other is close to !1.


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Barrons Data Analysis 1 (1)