STA 2023 Practice Test 3
For all problems, round calculated values to the same
number of places as the critical value from the table.
For confidence intervals, answers should be in algebraic
“between” form.
Make sure you designate whether the claim is Ho
or Ha !!
1) (9 points) For the population of
male college students, m = 69.0 inches and 
inches. A random
sample of 50 male students had 
= 69.6 inches. Test the claim that the mean is 69 with a =
.05.
DRAW IT!! Ho :
Ha :
One-tail or two-tail?
Test screen
Critical
value
Calculated
value
Decision (Reject Ho or Fail to reject Ho?)
Conclusion
statement:
2) (4 points) Find the 90% confidence interval for the population mean for #1. (round values to the nearest tenth).
Screen:
Conf.
Int.
3) (10 points) Sample statistics for 
= 24 are = 2.35 and 
= 0.7. With a =
.05, test the claim that the mean GPA is greater than 2.0.
DRAW
IT!! Ho :
Ha :
One-tail or two-tail?
Degrees
of freedom:
Critical
value:
Screen:
Calculated
value:
Decision:
Conclusion
statement:
4) (4 points) Find the 90% confidence interval for the population mean for #3 (to the nearest thousandth.)
Screen
Conf.
Int.
5) (9 points) Test the claim that the two samples come from populations with the same mean. Use a = .05.
Math majors: 
= 75, 
= 15
English majors: 
= 23, 
= 70, 
= 14
DRAW IT!! Ho :
Ha :
One-tail or two-tail?
p-value:
Screen:
Calculated value:
Decision:
Conclusion
statement
6) (4 points) Find the 90% confidence interval for the difference between the means for #5. ( round to the tenths place.)
Screen:
Conf.
Int.:
7) (9 points) Use a = .01 to test the claim that the two proportions are equal.
Faculty 
Students 
DRAW IT!! Ho :
Ha :
One-tail or two-tail?
Screen:
p-value:
Calculated value:
Decision:
Conclusion
statement
8)(4 points) Find the 98% confidence interval for the difference between the population proportions for #7 (round to the hundredths place)
Screen:
Conf. Int.