Question

A doctor wants to estimate the percentage of corona patients who develop symptoms after exposure. She wants a margin of error of 3% and she wants to be 99.8% confident.

Calculate the sample size for  of 40%.

   What value of  would give her the largest sample size?

Answer 1

Solution :

Given that,

= 0.40

1 - = 1 - 0.40 = 0.60

margin of error = E = 3% = 0.03

At 99.8% confidence level the z is ,

Z/2 = 3.09 ( Using z table )

Sample size = n = (Z/2 / E)2 * * (1 - )

= (3.09/ 0.03)2 * 0.40 * 0.60

= 2546.16

Sample size =2546