What is the standard deviation of the he final exam grade distribution for all students in the ntroductory statistics class at a local community college is displayed in the table, with A = 4, B = 3, C = 2, D = 1, and F = 0. Let X represent the grade for a randomly selected student from the class. O 1.16 O 1.08 O 1.41 O2.98 Grade 4 1 04 0 329.17 | 0.08 0.03 2.

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1538 and the standard deviation was 314. The test scores of four students selected at random are 1970, 1280, 2260, and 1430. Find the z-scores that correspond to each value and determine whether any of the values are unusual. .... The z-score for 1970 is (Round to two decimal places as needed.) The z-score for 1280 is (Round to two decimal places as needed.) The z-score for 2260 is (Round to two decimal places as needed.) The z-score for 1430 is. (Round to two decimal places as needed.) Which values, if any, are unusual? Select the correct choice below and, if necessary, fill in the answer box within your choice. O A. The unusual value(s) is/are (Use a comma to separate answers as needed.) O B. None of the values are unusual.

Body mass index (BMI) is a medical screening tool that measures body fat in an individual based on height and weight. The following data sets include four random samples of BMI measurements. Each sample includes the measurements of 7 individuals. Use the range rule of thumb to estimate the standard deviation, then determine which sample has the most variation. Sample 1 25.8,39.2,32.2,18.7,22.7,28.8,25.4 Sample 2 24.5,33.3,31.7,45.9,23.4,28.2,25.8 Sample 3 30.8,19.2,29.9,25.6,28.8,31.0,27.3 Sample 4 31.8,23.9,29.1,52.6,23.6,31.1,20.6

When Freshman 15 The term "Freshman 15" refers to the claim that college students typically gain 15 lb during their freshman year at college. Assume that the amounts of weight that male college students gain during their freshman year are normally distributed with a mean of 2.6 lb and a standard deviation of 10.8 1b (based on Data Set 13 "Freshman 15"). Find the probability that a randomly selected male college student gains 15 lb or more during his freshman year. What does the result suggest about the claim of the "Freshman 15"?

A researcher wants to know if there is a difference between the mean amount of sleep that people get for various types of employment status. The table below shows data that was collected from a survey. Full Time Worker Part Time Worker Unemployed 6 6 7 5 6 7 8 9 9 7 6 8 8 8 8 8 8 8 6 6 8 8 7   6 9   Assume that all distributions are normal, the three population standard deviations are all the same, and the data was collected independently and randomly. Use a level of significance of α=0.01α=0.01.H0: μ1=μ2=μ3H0: μ1=μ2=μ3H1:H1: At least two of the means differ from each other. For this study, we should use Select an answer 2-PropZTest 2-PropZInt 1-PropZInt 2-SampTInt 1-PropZTest T-Test χ²-Test ANOVA χ²GOF-Test TInterval 2-SampTTest  The test-statistic for this data =  (Please show your answer to 3 decimal places.) The p-value for this sample =  (Please show your answer to 4 decimal places.) The p-value is Select an answer less than (or equal to) alpha greater…

Is the difference between the mean annual salaries of registered nurses in State A and State B equal to $10,500? To decide, you select a random sample of registered nurses from each state. The results of each survey are shown. Assume the population standard deviations are o, $8337 and o, = $7633. At a = 0.01, what can you conclude? Registered Nurses in State A Registered Nurses in State B X1 75,695 70,695 %3D %3D X2 30 n2 25 What are the null and alternative hypotheses for this test? O A. Ho: H1 - H22 10,500 Ha: H1 - H2 10,500 Ha: H1 - H25 10,500 O F. Ho: H1 - H2s 10,500 Ha: H1 - H2 > 10,500 Determine the critical value(s). Zo = (Round to three decimal places as needed. Use a comma to separate answers as needed.)

n a school district, all sixth grade students take the same standardized test. The superintendant of the school district takes a random sample of 21 scores from all of the students who took the test. She sees that the mean score is 128 with a standard deviation of 41.4416. The superintendant wants to know if the standard deviation has changed this year. Previously, the population standard deviation was 25. Is there evidence that the standard deviation of test scores has increased at the α=0.005 level? Assume the population is normally distributed. Step 1 of 5 :  State the null and alternative hypotheses. Round to four decimal places when necessary.

The following table shows the number of people that have either 0, 1, 2 or 3 cars registered in their name from a sample of 166 people. Complete the table. xx CountCount 0 45 1 43 2 32 3 46 Find the mean number of cars owned for this sample. Give your answer to at least 2 decimal places. Find the standard deviation of cars owned for this sample. Give your answer to at least 2 decimal places.

The sizes of houses in Kenton County are normally distributed with a mean of 1369 square feet with a standard deviation of 171 square feet. For a randomly selected house in Kenton County, what is the probability the house size is under 1615 sq. ft. (round z to 2 decimal places & probability to 4 decimal places)? z = probability =

Listed below are systolic blood pressure measurements (mm Hg) taken from the right and left arms of the same woman. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Use a 0.05 significance level to test for a difference between the measurements from the two arms. What can be concluded? 143 140 141 136 133 Right arm Left arm 180 174 192 140 144 In this example, . is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the measurement from the right arm minus the measurement from the left arm. What are the null and alternative hypotheses for the hypothesis test? O A. Ho: Ha = 0 O B. Ho: Hd #0 0 = Prt :H O D. Ho: Hd =0 H O C. Ho: Ha 0 Identify the test statistic. t%3D (Round to two decimal places as needed.) Identify the P-value. P-value (Round to three decimal places as needed.) What is the conclusion based on the hypothesis test?…