Find the standard deviation of the data summarized in the given frequency distribution. The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency distribution below summarizes the results. Find the standard deviation. Round your answer to one decimal place. Waiting time Number of (minutes) customer 1.5 9 15 12 11 5.5 9.5 13.5 17.5 21.5

The scores and their percent of the final grade for a statistics student are given. What is the student's weighted mean score? The student's weighted mean score is. (Simplify your answer. Round to two decimal places as needed.) Homework Quiz Quiz Project Final Exam Score Percent of final grade 85 90 90 98 89 15 10 10 35 30

The decrease in cholesterol level (in mg/dL) for ten individuals are listed below. Calculate the range of the data. 16     22     17     18     22     19     21     20      18     23

The following histogram displays data from a cable repair company's in-home service calls. The technicians were asked to record how long each visit took. Approximately what percentage of service calls lasted less than 60 minutes? Round you answer to the nearest percent. Frequency 50- 40- 30 20- 10- 16 62-0 37 30-59 42 60-89 16 Or 90-119 Duration of a visit, mins 40 120-149 24 150-179