Question

Determine the sample size needed to construct a 95% confidence interval to estimate the average GPA for the student population at a college with a margin of error equal to 0.2. Assume the standard deviation of the GPA for the student population is 25 The sample size needed is (Round up to the nearest integer.) Determine the sample size n needed to construct a 90% confidence interval to estimate the population proportion for the following sample proportions when the margin of error equals 4%. a. p= 0.20 b. p=0.30 c. p = 0.40 Click the icon to view a table of standard normal cumulative probabilities a. n = (Round up to the nearest integer.) A producer of a variety of salty snacks would like to estimate the average weight of a bag of BBQ potato chips produced during the filling process at one of its plants. Determine the sample size needed to construct a 99% confidence interval with a margin of error equal to 0.007 ounces. Assume the standard deviation for the potato chip filling process is 0.05 ounces. The sample size needed is (Round up to the nearest integer)

Answer 1

Step1: The margin of error is E = 0.21 The standard deviation is o = 2.5 The z-table value is Zw/2 = 2008/2 = 2002 2/2 = 1.959964 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Step 2: The formula for calculating the sample size is = (1.959964.(25) = (4 892) = (24.49955) = 600.2279 »*601 Therefore, the sample size required is approximately n = 1601