Question 1

The data below show the average number of orders shipped daily (x) during the past 8 months and the average value of each order (y).Use the coefficient of variation to compare the degree of variation in each of the two data sets and use the result to identify which data set shows the greater degree of variation.

Accepted Answer

The answer of The data below show the average number...

Question 2

In a sample of five trading days, the number of shares traded (in 1000s) for two particular stocks appears in the table.Compute the correlation coefficient appropriate here.

Accepted Answer

The answer of In a sample of five trading days,...

Question 3

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

Accepted Answer

To find the proportion of service times between 3.5 and 4.6 minutes in a normal distribution, we calculate the z-score for 4.6 minutes. The z-score is (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation. For 4.6 minutes, the z-score is (4.6 - 3.5) / 1.1 = 1. Z-scores help us determine the proportion of data within certain ranges in a normal distribution. A z-score of 1 corresponds to a proportion of about 0.3413 (or 34.13%) above the mean in a standard normal distribution table. Since the question asks for the proportion between the mean and 4.6 minutes, and the distribution is symmetric around the mean, this value directly gives us the proportion in that range, which is approximately 0.3415 or 34.15%.

Question 4

Peak efficiency levels (in %) for the wind turbines at Miner's Point are shown for a sample of 10 days in April.Calculate the z-score for the value 69.0

Accepted Answer

The answer of Peak efficiency levels (in %) for the...

Question 5

The number of Cambodian college students studying abroad has increased over the last 6 years from 21,000 to 54,000.What was the average annual growth rate over this period?

Accepted Answer

The answer of The number of Cambodian college students studying...

Question 6

The table shows life expectancy in years of the G8 countries (Datablog, Guardian.co.uk, July 8 2009).Treating the data as a population, calculate the z-score for life expectancy in Russia.

Accepted Answer

The answer of The table shows life expectancy in years...

Question 7

The table below shows the civilian unemployment rate (%) and the growth rate of GDP (%) in the United States from 2008 to 2012 (Economic Report of the President).Treating the data as a sample, compute the covariance of the two sets of values.

Accepted Answer

The answer of The table below shows the civilian unemployment...

Question 8

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

Accepted Answer

The correct answer is A because the proportion of service times between 3.5 and 4.6 minutes is approximately 0.819, which is closest to choice A.

Question 9

Area car sales and home sales are listed for four sample months.Compute the covariance.Remember to treat the data as a sample.

Accepted Answer

The answer of Area car sales and home sales are...

Question 10

Area car sales and home sales are listed for four sample months.Compute the correlation coefficient.Remember to treat the data as a sample.

Accepted Answer

The answer of Area car sales and home sales are...

Question 11

The table below shows % growth in sales for five of Indiana's largest companies, along with the size of each company's capital investment (in $1000s) for the year.Compute the (population) covariance for the two sets of values.

Accepted Answer

The answer of The table below shows % growth in...

Question 12

The table below shows the civilian unemployment rate (%) and the growth rate of GDP (%) in the United States from 2009 to 2012 (Economic Report of the President).Treating the data as a sample, compute the correlation coefficient of the two sets of values.

Accepted Answer

The answer of The table below shows the civilian unemployment...

Question 13

Unit sales (in 1000s of units) for Kingston Products and Mile 10 Inc.are shown for the last four years.Compute the (population) covariance for the two sets of data.

Accepted Answer

The answer of Unit sales (in 1000s of units) for...

Question 14

Profits (in $millions) for Caldwell-Hewitt's US Division and European Division over the past four years are shown below.Compute the (population) correlation coefficient.

Accepted Answer

The answer of Profits (in $millions) for Caldwell-Hewitt's US Division...

Question 15

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

Accepted Answer

The answer of A particular data set follows the bell-shaped...

Question 16

The table summarizes the mean and the standard deviation of the supplier cost per liter of natural gas sold in four countries over the last 20 months.Using the coefficient of variation to measure cost volatility, rank order the countries from highest to lowest volatility.

Accepted Answer

The answer of The table summarizes the mean and the...

Question 17

The table below shows % growth in sales for five of Indiana's largest companies, along with the size of each company's capital investment (in $1000s).Compute the (population) correlation coefficient for the two sets of values.

Accepted Answer

The answer of The table below shows % growth in...

Question 18

As measured by the coefficient of variation, which data set shows the greater degree of variation?

Accepted Answer

The answer of As measured by the coefficient of variation,...

Question 19

In a sample of five trading days, the number of shares traded (in 1000s) for two particular stocks appears in the table.Compute the sample covariance for temperature and crime rate.

Accepted Answer

The answer of In a sample of five trading days,...

Question 20

The population of Ecuador rose from 9.9 million in 1996 to 15.0 million in 2013.Using the geometric mean, compute the average annual rate of increase over this 17-year period.

Accepted Answer

The geometric mean rate of increase, $r$, is found using the formula for growth: $Final = Initial \times (1 + r)^{n}$, where $n$ is the number of periods. Rearranging to solve for $r$, we get $r = \left(\frac{Final}{Initial}\right)^{\frac{1}{n}} - 1$. Plugging in the given values: $r = \left(\frac{15.0}{9.9}\right)^{\frac{1}{17}} - 1$, which approximately equals 0.0247 or 2.47% when converted to a percentage.

Quiz 3: Descriptive Statistics II: Additional Descriptive Measures and Data Displays

In a sample of five trading days, the number of shares traded (in 1000s) for two particular stocks appears in the table.Compute the correlation coefficient appropriate here.

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

Peak efficiency levels (in %) for the wind turbines at Miner's Point are shown for a sample of 10 days in April.Calculate the z-score for the value 69.0

The number of Cambodian college students studying abroad has increased over the last 6 years from 21,000 to 54,000.What was the average annual growth rate over this period?

The table shows life expectancy in years of the G8 countries (Datablog, Guardian.co.uk, July 8 2009) .Treating the data as a population, calculate the z-score for life expectancy in Russia.

The table below shows the civilian unemployment rate (%) and the growth rate of GDP (%) in the United States from 2008 to 2012 (Economic Report of the President) .Treating the data as a sample, compute the covariance of the two sets of values.

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

Area car sales and home sales are listed for four sample months.Compute the covariance.Remember to treat the data as a sample.

Area car sales and home sales are listed for four sample months.Compute the correlation coefficient.Remember to treat the data as a sample.

The table below shows % growth in sales for five of Indiana's largest companies, along with the size of each company's capital investment (in $1000s) for the year.Compute the (population) covariance for the two sets of values.

The table below shows the civilian unemployment rate (%) and the growth rate of GDP (%) in the United States from 2009 to 2012 (Economic Report of the President) .Treating the data as a sample, compute the correlation coefficient of the two sets of values.

Unit sales (in 1000s of units) for Kingston Products and Mile 10 Inc.are shown for the last four years.Compute the (population) covariance for the two sets of data.

Profits (in $millions) for Caldwell-Hewitt's US Division and European Division over the past four years are shown below.Compute the (population) correlation coefficient.

A particular data set follows the bell-shaped pattern of a normal distribution, with a mean of 3.5 minutes and a standard deviation of 1.1 minutes.What proportion of service times will be between 3.5 and 4.6 minutes?

The table summarizes the mean and the standard deviation of the supplier cost per liter of natural gas sold in four countries over the last 20 months.Using the coefficient of variation to measure cost volatility, rank order the countries from highest to lowest volatility.

The table below shows % growth in sales for five of Indiana's largest companies, along with the size of each company's capital investment (in $1000s) .Compute the (population) correlation coefficient for the two sets of values.

As measured by the coefficient of variation, which data set shows the greater degree of variation?

In a sample of five trading days, the number of shares traded (in 1000s) for two particular stocks appears in the table.Compute the sample covariance for temperature and crime rate.

The population of Ecuador rose from 9.9 million in 1996 to 15.0 million in 2013.Using the geometric mean, compute the average annual rate of increase over this 17-year period.