A researcher wishes to estimate with 95 confidence the propo

A researcher wishes to estimate, with 95% confidence, the proportion of adults who have high-speed Internet access, Her estimate must be accurate within 4% of the true proportion. the respondents said they have high speed internet access a Find the minimum sample needed using a priorstudy that found 38% of estimate is available. Find the minimumsample size needed. a) what is the minimum sample size needed using a prior study that found that 38% of the respondents said they have high-speed Internet access? a n- (Round up to the nearest whole number as needed) n (Round up to the nearest whole number as needed)

Solution

95% confidence

Accurate to within 4%

38% had said they have high speed access.

For 95% confidence, z = 1.96
Error = 4% = 0.04
SD = sqrt(0.38 * (1 - 0.38)) --> sqrt(0.38 * 0.62) = 0.4853864439804639

Sample size n is :

n = [(1.96)( 0.4853864439804639)/ 0.04]^2

n = 565.675

n = 566 ---> ANSWER

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SD =sqrt(0.5 * (1 - 0.5)) = sqrt(0.5*0.5) = 0.5

n = [(1.96)(0.5) / 0.04]^2

n = 600.25

n = 600 ---> ANSWER