Exam 11: Statistics

The ages of 40 community college students were gathered. Construct a frequency distribution for the data using five classes.

These data represent the number of stray cats in a small town for the years listed. Draw a time series graph for the data.

Find the area under the normal distribution curve between z = 0 and z = 2.35.

Twelve students took a placement exam with the following results. What is the percentile rank of 64? Round to the nearest percentile.

If a student's rank in a class of 200 students is 12, find the student's percentile rank.

Consider the survey question "Do you feel that it is not appropriate to have areas where people Cannot smoke?" Why do you think the question is a poor one?

Find the area under the normal distribution curve between z = 0 and z = -1.35.

Construct a stem and leaf plot for the following data using whole numbers as stems and the decimals as leaves.

A data set of size 21 has correlation coefficient of r = 0.476. Test the significance of r at the 5% Level and at the 1% level.

Find the equation of the regression line.

Draw a bar graph illustrating the change in a state's tax rate on each of the axes below. Note that you'll be using the same information on each graph. \ Which of the two bar graphs would be used by someone wanting to argue that this tax cut won't hurt the state's budget much? Why?

Find the value for the correlation coefficient r.

Construct a stem leaf plot for the following data.

Assume a data set is normally distributed with mean 17 and standard deviation 1.5. If the data set Contains 40 data values, approximately how many of the data values will fall within the range 15.5 To 18.5?

Find the value for r and test the significance of r at the 5% level.

Fifty 10-year-olds were monitored to determine the number of hours per week they spent watching television, surfing the net, and playing video games. The results were used to obtain the frequency distribution below. Construct a histogram and frequency polygon for the data.

To obtain the frequency distribution below, twenty-three babies were monitored for how many times they cried during the night. Construct a histogram for the data.

For the following data (a)Draw a scatter plot. (b)Find the value for r. (c)Test the significance of r at the 5% level and at the 1% level. (d)If r is significant, find the regression line and draw the line on the scatter plot. (e)Describe the nature of the relationship if one exists. (f)

Suppose that the mean sale price for existing homes in the United States in is $219,300. Assume that sale prices are normally distributed with a standard deviation of $44,000. a. Fill in the blanks below the normal curve with the appropriate information. Find the percentage of existing homes that: b. sold for between $131,300 and $307,300 c. sold for more than $263,300

A researcher is studying possible grade inflation at colleges. The sample is .