Question

A survey of 121 randomly selected students at one college show that only 88 checked their campus email account on a regular basis. Construct a 98% confidence interval for the percentage of students at the college who do not check their email account on a regular basis. Round to one decimal place

Answer 1

The number of students who do not check their e-mail accounts on a regular basis is 121-88=33.

And the proportion for that is 33/121 = 0.27 which is a percentage of 27%

Now let's write the information we have :

sample size ---> n=121

and we have a proportion of 0.27 as we calculated before, so:

Now let's replace the information we already have in the equation provided:

Finally the confidence interval for the percentage of students at the college who do not check their email account on a regular basis is 17.6% < p < 36.4%

The lower endpoint is: 17.6%

The upper endpoint is: 36.4%