# Question: From Example 7 trading volumes for General Electric stock on

From Example 7, trading volumes for General Electric stock on Mondays and Fridays during

February through April of 2011 were given as follows

The Monday data have x = 51.82, s = 17.19, Q1 = 43, Median = 45, Q3 = 64.

The Friday data have x = 50, s = 11.34, Q1 = 41.5, Median = 47, Q3 = 54.5.

a. Construct a histogram or box plot of the Friday data. What assumptions are needed to construct a 95% confidence interval for μ? Point out any assumptions that seem questionable.

b. Using the Friday data and appropriate given summary statistics, show that the 95% confidence interval is (42.795, 57.205). Interpret it in context.

c. Check whether this data set has any potential outliers according to the criterion of (i) 1.5 * IQR below Q1 or above Q3 and (ii) 3 standard deviations from the mean.

d. The value 80 is quite a bit larger than the others. Delete this observation, find the new mean and standard deviation, and use software to construct the 95% confidence interval for μ. How does it compare to the 95% confidence interval (42.796, 57.204) using all the data?

February through April of 2011 were given as follows

The Monday data have x = 51.82, s = 17.19, Q1 = 43, Median = 45, Q3 = 64.

The Friday data have x = 50, s = 11.34, Q1 = 41.5, Median = 47, Q3 = 54.5.

a. Construct a histogram or box plot of the Friday data. What assumptions are needed to construct a 95% confidence interval for μ? Point out any assumptions that seem questionable.

b. Using the Friday data and appropriate given summary statistics, show that the 95% confidence interval is (42.795, 57.205). Interpret it in context.

c. Check whether this data set has any potential outliers according to the criterion of (i) 1.5 * IQR below Q1 or above Q3 and (ii) 3 standard deviations from the mean.

d. The value 80 is quite a bit larger than the others. Delete this observation, find the new mean and standard deviation, and use software to construct the 95% confidence interval for μ. How does it compare to the 95% confidence interval (42.796, 57.204) using all the data?

## Relevant Questions

Exercise 8.6 reported heights (in mm) of 55.5, 60.3, 60.6, 62.1, 65.5, and 69.2 for six seedlings fourteen days after germination. a. Using software or a calculator, verify that the 95% confidence interval for the population ...Example 7 analyzed the trading volume of shares of General Electric stock between February and April 2011. Summary statistics of the data were calculated using MINITAB and are shown below: The 95% confidence intervals for ...A company that sells its products through mail-order catalogs wants information about the success of its most recent catalog. The company decides to estimate the mean dollar amount of items ordered from those who received ...How large a sample size do we need to estimate the mean annual income of Native Americans in Onondaga County, New York, correct to within $1000 with probability 0.99? No information is available to us about the standard ...In February 2002, the Associated Press quoted a survey of 3000 British residents conducted by YouGov.com. It stated, “Only 21% wanted to see the monarchy abolished, but 53% felt it should become more democratic and ...Post your question