The random variable X has a normal distribution. The mean is (where > 0) and the variance is

0.252

. TheP(X > 1.5) is equal to:

An insurance company states that it settles 80% of all life insurance claims within 30 days. A consumer group believe that the true proportion of the settled claims is less than 80% and they ask the state insurance commission to investigate. It was found that in a sample of 300 life insurance claims, 225 were settled within 30 days. Find the appropriate alternative hypothesis and the corresponding decision at 3% level of significance.

At a fast food restaurant, the probability that someone uses the drive-through is 0.7. The probability that they order a combo is 0.38. The probability that someone order a combo and use the drive through is 0.28. What is the probability that someone doesn't use the drive-through and doesn't order a combo? (Hint: use a Venn Diagram)

A tire manufacturer would like to determine how weather conditions and speed affect the stopping distance of a vehicle using a certain type of tire. An experiment will be conducted on a test track under simulated weather conditions (either dry, rain orice) and at different speeds (40 km/h, 60 km/h, 80 km/h or 100 km/h, 120 km/h). Each combination of factor levels will be tested in three trial runs, and the same vehicle and the same set of tires will be used for each run. Howmanytreatment(s)is/are in this experiment?

What sample size should be chosen in order to find the mean number of absences per month for school children.The margin of error is +/- 0.2 at a 99% confidence level; the population standard deviation is 1.00?

Forty-one female volunteers took a new diet pill for three months. Weight loss in pounds during these three months was recorded to calculate a 98% confidence interval for the mean weight loss: 8.3lb+/- 0.29 lb. What are the mean and standard deviation for this sample

Event A has a probability of 0.2 of occurring.Event B has a probability of 0.5 of occurring.If A and B are Independent, then the probabilityP(A or B)is

A tobacco company claims that the true mean tar content for its cigarette is less than 16 mg. To test their claim a sample of 10 cigarettes were randomly selected. The mean and standard deviation of the tar contents of this sample were 15.85 mg and 0.35 mg. If the tar content of this company's cigarettes is known to follow a normal distribution with standard deviation 0.3,what is theP-value of the test?