Homework SourseA researcher wishes to estimatewith 90 confidence the propor
| A researcher wishes to estimate,with 90% confidence, the proportion of adults who have high speed internet access.Her estimate must be accurate within 5% of the true proportion. a)Find the minimum sample need, using a prior study that found that 32% of the respondents said they have high speed internet access.n=? b)no preliminary estimate is available.Find the minimum sample size needed.n=? |
| A researcher wishes to estimate,with 90% confidence, the proportion of adults who have high speed internet access.Her estimate must be accurate within 5% of the true proportion. a)Find the minimum sample need, using a prior study that found that 32% of the respondents said they have high speed internet access.n=? b)no preliminary estimate is available.Find the minimum sample size needed.n=? |
Solution
a)
Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.1 is = 1.64
Samle Proportion = 0.32
ME = 0.05
n = ( 1.64 / 0.05 )^2 * 0.32*0.68
= 234.1028 ~ 235
b)
Compute Sample Size ( n ) = n=(Z/E)^2*p*(1-p)
Z a/2 at 0.1 is = 1.64
Samle Proportion = 0.5
ME = 0.05
n = ( 1.64 / 0.05 )^2 * 0.5*0.5
= 268.96 ~ 269
