Javier and Ercilia are supervisors at a shopping mall. Each was given the task of estimating the mean distance that shoppers live from the mall. They each randomly surveyed 100shoppers. The samples yielded the following information.

a. How can you determine which survey was correct ?

b. Explain what the difference in the results of the surveys implies about the data.

c. If the two histograms depict the distribution of values for each supervisor, which one depicts Ercilia's sample? How do you know?

d. If the two box plots depict the distribution of values for each supervisor, which one depicts Ercilia’s sample? How do you know?

Use the following information to answer the next three exercises: We are interested in the number of years students in a particular elementary statistics class have lived in California. The information in the following table is from the entire section.

Short Answer

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(a) The sample variance gives the variability of the sample data. The survey with minimum variance is correct.

(b) Both the survey has same mean but different variance (sd).

The variance can be used to determine the relation between the individual numbers with each other within a data set. In this, Javier's sample has more variability than Ercilia's sample.

(c) The histogram (b) is Ercilia's samples.

(d) Boxplot (b) shows Ercilia's samples.

Step by step solution

01

Survey : 

To create a map, plan, or description, examine and record the extent and features.

02

(a) Explanation :

Javier and Ercilia are supervisors at a shopping mall. Each of them was given the task of estimating the mean distance that shoppers live from the mall. They randomly surveyed 100shoppers. The samples yield are,

The sample variance gives the variability of the sample data. The survey with minimum variance is correct.

03

(b) Explanation : 

Javier and Ercilia are supervisors at a shopping mall. Each of them was given the task of estimating the mean distance that shoppers live from the mall. They randomly surveyed 100shoppers. The samples yield are,

Both the survey has same mean but different variance(sd).

The variance can be used to determine the relation between the individual numbers with each other within a data set. In this, Javier's sample has more variability than Ercilia's sample.

04

(c) Explanation : 

Javier and Ercilia are supervisors at a shopping mall. Each of them was given the task of estimating the mean distance that shoppers live from the mall. They randomly surveyed

100shoppers. The samples yield are,

The histogram (a) has less variability and (b) has more variability.

Hence, the histogram (b) is Ercilia's samples.

05

(d) Explanation : 

Javier and Ercilia are supervisors at a shopping mall. Each of them was given the task of estimating the mean distance that shoppers live from the mall. They randomly surveyed 100shoppers. The samples yield are,

The boxplot explains the range and the IQR, both are measures of the variations.

The IQR of the boxplot (a) =14-1=13

The IQR of the boxplot (b) = 9-4=5

Hence, the boxplot (b) has more variability than (a).

Boxplot (b) shows Ercilia's samples.

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Most popular questions from this chapter

Forty randomly selected students were asked the number of pairs of sneakers they owned. Let X= the number of pairs of sneakers owned. The results are as follows:

a. Find the sample meanx¯.

b. Find the sample standard deviation, s

c. Construct a histogram of the data.

d. Complete the columns of the chart.

e. Find the first quartile.

f. Find the median.

g. Find the third quartile.

h. Construct a box plot of the data.

i. What percent of the students owned at least five pairs?

j. Find the 40thpercentile.

k. Find the 90thpercentile.

l. Construct a line graph of the data.

m. Construct a stemplot of the data.

Construct a times series graph for

(a) the number of male births,

(b) the number of female births, and

(c) the total number of births.

Use the following information to answer the next two exercises. Sixty-five randomly selected car salespersons were asked the number of cars they generally sell in one week. Fourteen people answered that they generally sell three cars; nineteen generally sell four cars; twelve generally sell five cars; nine generally sell six cars; eleven generally sell seven cars.

Looking at your box plot, does it appear that the data are concentrated together, spread out evenly, or concentrated in some areas, but not in others? How can you tell?

The following data show the different types of pet food stores in the area carry. 6;6;6;6;7;7;7;7;7;8;9;9;9;9;10;10;10;10;10;11;11;11;11;12;12;12;12;12;12; Calculate the sample mean and the sample standard deviation to one decimal place using a TI-83+orTI-84 calculator.

The following table is a portion of a data set from www.worldbank.org. Use the table to construct a time series graph for CO2 emissions for the United States.

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