What percentage of college students are attending a college in the state where they grew up? Let p be the proportion of college students from the same state as that in which the college resides. If no preliminary study is made to estimate p, how large a sample is needed to be 90% sure that the point estimate (p hat) will be within a distance of 0.07 from p?

Question

Jordan · Accepted Answer

139

MathGuru · Answer

Try this formula:
n = [(z-value)^2 * p * q]/E^2
= [(1.645)^2 * .5 * .5]/0.07^2
= ? (round to the next highest whole number)

I'll let you finish the calculation.

Note: n = sample size needed; .5 for p and .5 for q are used if no value is stated in the problem. E = maximum error, which is 0.07 in the problem. Z-value is found using a z-table (for 90%, the value is 1.645).

I hope this will help get you started.

carla · Answer

r=-.96 between craving for pizza and ability to concentrate on studying