Use the expression in the accompanying discussion of sample size to find the size of each sample if you want to estimate the difference between proportions of men and women who own smartphones. Assume that you want 99​% confidence that your error is no more than 0.03. The sample should include ______ men and ______ women.

Concrete. As concrete cures it gains strength. Table 5 lists the 7-day strength (in pounds per square inch) and the 28-day strength (in pounds per square inch) of ten randomly selected samples. Questions 5A to 5F Answer the questions based on the data in Table 5. 5A. What is the value of r? 5B. What is the coefficient of determination? 5C. Interpret the coefficient of determination. 5D. Find the standard error of estimate, se. Table 5. 7-day and 28-day strength (in pounds per square inch) 7-day strength, z 3004 2716 2784 3042 3106 3050 3205 2827 2869 3171 28-day strength, y 4401 4042 4155 4460 4530 4475 4675 4175 4260 4635 5E. Use regression to predict the 28-day strength of concrete with a 7-day strength of 3000 pounds per square inch. 5F. Construct a 99% prediction interval for the population mean 28-day strength for concrete with a 7-day strength of 3000 pounds per square inch.

solve sub parts d-f

You want to estimate the percentage of statistics students who get grades of C or better. How many students should you survey to be 95% confident that the sample percentage is off by no more than 2 percentage points.