An urban planner claims that nationally 20% of all families renting condominiums move during the year. A random sample of 200 families renting condominiums in a large development revealed that 28% had moved during the past year. Construct a 90% confidence interval for the population percent of families who moved during the past year.  

The average age for UVU students is 24.6 years, with a standard deviation of 2.8 years.  Assume a normal distribution.  What is the probability of selecting a sample of 200 students with an average age that is less than 24?

Two randomly selected groups of 200 students each were taught two different memorization methods over a four week period. At the end of four weeks a memorization test with a maximum possible score of 100 was given. The confidence interval of the difference in the two group population mean scores on the memorization test was (0.8 to 1.4). What statement best reflects the results of this study?

A company has 300 employees. Each year, there is a 30% turnover rate for the employees. The total number of employees who leave each year follows a binomial distribution. Now, we want to use the normal approximation to this binomial distribution. Then in this normal distribution, the mean is ______ and the standard deviation is _____.

A poll of 120 adults who shopped at Walmart found that 54 have purchased a flat screen television Based on these data, what is the margin of error for a 95% confidence interval of the proportion of adults who have purchased a flat screen television.