In: Statistics and Probability
In a recent survey of 150 students at a large community college, 86 students said they were “regular” coffee drinkers. It is known that 64% of all students at that community college are “regular” coffee drinkers. Use this information to compute necessary quantities, and fill in the blanks: The average distance between the values of the sample proportion (from all possible random samples of 150 students from this community college) of "regular" coffee drinkers and the population proportion 0.64 of "regular" coffee drinkers in this community college is approximately_________. We estimate that the values of the sample proportion (from all possible random samples of 150 students from this community college) of "regular" coffee drinkers vary from the population proportion of "regular" coffee drinkers in this community college of 0.64 by about _________ , on average.
Sample size (n) = 150 (i.e. total number of students in
survey)
no of coffee drinkers = 86
1. Explanation:
Average distance between values of sample proportion and population proportion =
2. Explanation:
Before making any estimation of the average difference, we have to consider a particular confidence level. 95% confidence level in industry standard. Hence, We will find confidence interval of this average.
For this, We have to calculated standard error. In case of proportion, formula of Standard error is,
Z- statistics for 95% confidence level (with two tails) = 1.96
Hence, with 95% confidence, we can say that " sample proportion is estimated to vary from population proportion by about -14.35% to 1.01%, on average".