SOLUTION: Out of a sample of 100 students, 25 indicated that they preferred chocolate ice cream to vanilla ice cream. a. Estimate the value of the population proportion of those who pref

Algebra ->  Probability-and-statistics -> SOLUTION: Out of a sample of 100 students, 25 indicated that they preferred chocolate ice cream to vanilla ice cream. a. Estimate the value of the population proportion of those who pref      Log On


   

Question 1193014: Out of a sample of 100 students, 25 indicated that they preferred chocolate ice cream to vanilla ice cream.

a. Estimate the value of the population proportion of those who preferred chocolate ice cream. (Round the final answer to 3 decimal places.)
b. Compute the standard error of the proportion. (Round the final answer to 4 decimal places.
c. Determine a 80% confidence interval for the population proportion of those who preferred chocolate ice cream. (Round the final answers to 3 decimal places.)
d. Interpret your findings.
If 100 such intervals were determined, the population
proportion would be included in about --- intervals.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
a. phat = 0.25 It's the best guess there is.
b. this is sqrt (0.25*0.75/100)=0.0433
c. 80% half-interval is 1.28(0.0433) using abs z(0.10). This is 0.056
The interval is (0.194, 0.306)
d. would be included in about 80 intervals. We wouldn't know which 80 of course.