Question

A random sample of biostatistics students will be taken to estimate the proportion of students who were also in Calculus II. What sample size would be necessary to propotion to within margin of error 0.10 with 90% confidence? Suppose it is known from the past that such propotion may be between 0.75 and 0.82. What is the size that you need? a. 46 b. 50 c. 45

Answer 1

o Given will be A random Sample of students will be taken to estimate the propostion of stu we need to find the sample size needed for propostion ie, for , marging froor (E) = 0.10 proportion between 0.75 and 0.82 hie, pe 0.75 +0.82 = 1.57 -0.785 P=0.785 q=1-0.785 = 0.215 Sample size ) = # å tale) ² ( e for 90of confidence Zd2 = 1.645 = 0.985 * 0.25 * 1.645 = 45.6709 ~ 46, c. Sample size needed (m) = 46