8.5 Practice Due Fri. 5/10 - WENDY NOSAL | Library

Required

3

A “classic rock” radio station claims to play an average of 50 minutes of music every hour. However, it seems that every time you tune into this station, a commercial is playing. To investigate the station’s claim, you randomly select 12 different hours during the next week and record how many minutes of music the station plays in each of those hours. Here are the data:
48 49 45 51 49 53 48 44 47 50 46 48

You would like to perform a test to see if the average of 50 minutes of music every hour is actually an exaggeration.
Identify the null and alternative hyothesis.
Define the parameter of interest.

Required

5

A “classic rock” radio station claims to play an average of 50 minutes of music every hour. However, it seems that every time you tune into this station, a commercial is playing. To investigate the station’s claim, you randomly select 12 different hours during the next week and record how many minutes of music the station plays in each of those hours. Here are the data:
48 49 45 51 49 53 48 44 47 50 46 48

You would like to perform a test to see if the average of 50 minutes of music every hour is actually an exaggeration.
Confirm that the conditions for conducting a significance test for a mean have been met:

Required

5

A “classic rock” radio station claims to play an average of 50 minutes of music every hour. However, it seems that every time you tune into this station, a commercial is playing. To investigate the station’s claim, you randomly select 12 different hours during the next week and record how many minutes of music the station plays in each of those hours. Here are the data:
48   49   45   51   49   53   48   44   47   50   46   48

You would like to perform a test to see if the average of 50 minutes of music every hour is actually an exaggeration.
Use statsmedic.com/applets, 1 quantitative variable single group, to find the mean and standard deviation.
What is the sample mean? _______ round to 3 places past the decimal
What is the mean from the null hypothesis? _______ 
What is the standard error for the sampling distribution of the mean? _______ Round to 3 places past the decimal. See 8.5 for the formula if needed.
Calculate the standardized test statistic (the t statistic) _______ round to 3 places
 .   

Required

4

A “classic rock” radio station claims to play an average of 50 minutes of music every hour. However, it seems that every time you tune into this station, a commercial is playing. To investigate the station’s claim, you randomly select 12 different hours during the next week and record how many minutes of music the station plays in each of those hours. Here are the data:
48   49   45   51   49   53   48   44   47   50   46   48
You would like to perform a test to see if the average of 50 minutes of music every hour is actually an exaggeration.
Degrees of freedom = _______ 
Is this a one tailed or a two tailed test? Enter 1 or 2 _______ 
Use the absolute value of the t statistic.
What are the two percentages that correspond to these values? Enter in the same order, keep in decimal form.
 _______  to  _______

Required

3

Based on the results in the previous question, using an alpha level of 5%, do you have convincing evidence that the radio station is exaggerating about the number of minutes of music they play each hour?

Required

3

A professor suspects that students at his school are getting fewer than 8 hours of sleep a night, on average. To test his belief, the professor asks a random sample of 28 students, “How much sleep did you get last night?”
Here are the data (in hours):
9 6 8 6 8 8 6 6.5 6 7 9 8 7 7
4 3 4 5 6 11 6 3 6 6 10 7 4.5 9

The professor wants to perform a test at the α = 0.05 significance level.

Identify the null and alternative hypotheses.
Define the parameter of interest.

Required

5

A professor suspects that students at his school are getting fewer than 8 hours of sleep a night, on average. To test his belief, the professor asks a random sample of 28 students, “How much sleep did you get last night?”
Here are the data (in hours):
9 6 8 6 8 8 6 6.5 6 7 9 8 7 7
4 3 4 5 6 11 6 3 6 6 10 7 4.5 9

The professor wants to perform a test at the α = 0.05 significance level.

Check that the conditions for performing the test are met.
Five answers please.

Required

5

A professor suspects that students at his school are getting fewer than 8 hours of sleep a night, on average. To test his belief, the professor asks a random sample of 28 students, “How much sleep did you get last night?”
Here are the data (in hours):
9  6  8  6  8  8  6  6.5  6  7  9  8  7  7
4  3  4  5  6  11  6  3  6  6  10  7  4.5  9

The professor wants to perform a test at the α = 0.05 significance level.
Use statsmedic.com/applets, 1 quantitative variable single group, to find the mean and standard deviation.
What is the sample mean? _______ keep all decimal places
What is the mean from the null hypothesis? _______ 
What is the standard error for the sampling distribution of the mean? _______ Round to 3 places past the decimal. See 8.5 for the formula if needed.
Calculate the standardized test statistic (the t statistic) _______ round to 3 places
 .   

Required

4

A professor suspects that students at his school are getting fewer than 8 hours of sleep a night, on average. To test his belief, the professor asks a random sample of 28 students, “How much sleep did you get last night?”
Here are the data (in hours):
9  6  8  6  8  8  6  6.5  6  7  9  8  7  7
4  3  4  5  6  11  6  3  6  6  10  7 4.5  9

The professor wants to perform a test at the α = 0.05 significance level. Continue with the significance test from above.
Degrees of freedom = _______ 
Is this a one tailed or a two tailed test? Enter 1 or 2 _______ 
Use the absolute value of the test statistic.
What are the two percentages that correspond to these values? Enter in the same order
 _______   to  _______

Required

3

Based on the results in the previous question, using an alpha level of 5%, do you have convincing evidence that the professor's students don't get the required 8 hours of sleep?