Exam 26: Understanding Probability Distributions and Statistical Inference

Use the following to answer the question(s) below. A survey of investors finds that 60% use a full service brokerage firm to invest in stocks, 30% trade stocks online and 24% do both. -The probability that an investor selected at random neither uses a full service brokerage firm to invest in stocks nor trades stocks online is

Use the following to answer the question(s) below. Insurance company records indicate that 10% of its policyholders file claims involving theft or robbery of personal property from their homes. Suppose a random sample of 400 policyholders is selected. -What is probability that the sample proportion of policyholders filing claims involving theft or robbery of personal property from their homes exceeds 15%?

Use the following to answer the question(s) below. An advocacy group is investigating whether gender has an effect on job category in large investment firms. They surveyed a sample of firms with the following results: -What is the probability that a randomly selected employee's job category is executive/managerial, given that the employee is female?

Use the following to answer the question(s) below. Chris Columbus is responsible for controlling inventory levels for four types of sailboats sold by his company. Chris takes a sample of 48 boats sold over the past several months to determine if demand is the same for each type. His results are as follows: -At the 0.05 level of significance, the correct conclusion is

Use the following to answer the question(s) below. A men's clothing store has determined the following probability distribution for the number of special size orders placed per month. The distribution is as follows: Number Ordered Probability 0 0.10 5 0.10 10 0.12 15 0.30 20 0.38 -The standard deviation of the number of special size orders placed per month is

We have calculated a 95% confidence interval and would like our next confidence interval to have a smaller margin of error without losing any confidence. In order to do this, we can

Use the following to answer the question(s) below. An advocacy group is investigating whether gender has an effect on job category in large investment firms. They surveyed a sample of firms with the following results: -What is the probability that a randomly selected employee's job category is executive/managerial?

Use the following to answer the question(s) below. IT staff for a large corporation has developed the following probability distribution for the number of calls requiring troubleshooting problems per day. -What is the probability that the sample mean will be less than 7.5 minutes?

Use the following to answer the question(s) below. The weights of soy patties sold by Veggie Burgers Delight are normally distributed. A random sample of 15 patties yields a mean weight of 108 grams with a sample standard deviation of 14 grams. At the 0.05 level of significance, perform a hypothesis test to see if the true mean weight is less than 113 grams. -The correct conclusion at the 0.05 level of significance is

Use the following to answer the question(s) below. Shape-Up-By-Susie claims that participating in her exercise program will result in guaranteed weight loss in just 6 weeks. Five clients weighed themselves before and then again after participating in her program and the differences "weight after - weight before" were analyzed. Below is the relevant computer output. -Which of the following statement is true?

Use the following to answer the question(s) below. Chris Columbus is responsible for controlling inventory levels for four types of sailboats sold by his company. Chris takes a sample of 48 boats sold over the past several months to determine if demand is the same for each type. His results are as follows: -The calculated value of the Chi-square statistic is

Use the following to answer the question(s) below. Shape-Up-By-Susie claims that participating in her exercise program will result in guaranteed weight loss in just 6 weeks. Five clients weighed themselves before and then again after participating in her program and the differences "weight after - weight before" were analyzed. Below is the relevant computer output. -At the 0.05 level of significance, the correct conclusion is

Use the following to answer the question(s) below. An advocacy group is investigating whether gender has an effect on job category in large investment firms. They surveyed a sample of firms with the following results: -Two events F = {a randomly selected employee is female} and S = {a randomly selected employee's job category is professional staff} are