Question

According to the Oxnard College Student Success Committee report in the previous year, we believe that 23% of students struggle in their classes because they don't spend more than 8 hours studying independently outside of a 4-unit class. For this year, you would like to obtain a new sample to estimate the proportiton of all Oxnard students who struggle in their classes because they don't study enough outside of the classrooms. You would like to be 90% confident that your estimate is within 1% of the true population proportion. How large of a sample size is required? Do not round mid-calculation. n =

Answer 1

According to  Oxnard College Student Success Committee report in the previous year; Percentage of students struggle in their classes because they don't spend more than 8 hours studying independently outside of a 4-unit class = 23% i.e

According to  Oxnard College Student Success Committee report in the previous year Proportion of of students struggle in their classes because they don't spend more than 8 hours studying independently outside of a 4-unit class :p_g = 23/100=0.23

90% confident that your estimate is within 1% of the true population proportion

Confidence interval : 90%

for 90% confidence level = 100-90/100= 0.10

/2 = 0.10/2 = 0.05

Margin of error: E = 1/100 = 0.01

Formula for Sample size required : n

Z_0.05 = 1.645

Sample size required : n for 90% confidence interval

Sample size required : n = 4792