WorksheetsSample size and t student
Total questions: 7
Worksheet time: 27mins
Name
Class
Date
1.
What is the t value associated with 90% confidence and a sample size of 15?
a)
1.341
b)
1.345
c)
1.761
d)
1.753
2.
What is the degrees of freedom equal to?
a)
n
b)
n+1
c)
1-n
d)
n-1
3.
A local bank needs information concerning the savings account balances of its customers. A random sample of 13 accounts was checked. The mean balance was $686.75 with a sample standard deviation of $256.20. Find a 95% confidence interval for the true mean.
a)
($513.14, $860.36)
b)
($525.59, $847.91)
c)
($533.27, $840.23)
d)
($531.92, $841.58)
4.
The 90% interval for a statistics test was given by 72 +- 7. What is the lower bound for the interval?
a)
7
b)
72
c)
65
d)
79
5.
A 90% confidence interval for the mean speed driven by cars on East Main St. is given by (21, 45). What was the sample mean of this study?
a)
12
b)
24
c)
33
d)
None of these.
6.
A sample of 20 cupcakes found the interval for calories to be (150, 350). Which is the correct interpretation of the 95% confidence interval?
a)
We are 95% confident that the true mean calorie content can be found with a sample of 150 to 350 cupcakes.
b)
We are 95% confident that the true mean calorie content in cupcakes is between 150 and 350 calories.
c)
We are 95% confident that a sample of 20 cupcakes will find 250 calories per cupcake.
d)
None of these are correct.
7.
Find the t* value for a 99% confidence interval with a sample of 23 people.
a)
1.714
b)
1.711
c)
2.064
d)
None of these.
100 %
