A study of working actors looked at age and gender. One sample of 55 male actors had a mean age of 32 and a standard deviation of 2. The other sample included 55 female actors with a mean age of 28 and a standard deviation of 4. Estimate with 90% confidence the difference between the average ages of working male (μ1) and female (μ2)actors. Round answers to the nearest hundredth. < μ1 - μ2 <

The ages of people living in a retirement community are normally distributed with a mean age of 68 years and a standandard deviation of 4 years. Use the Empirical Rule to find the percentage of people in the community whose ages are less than 60. Give your answer with one decimal place.

It takes an average of 13.2 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will decline if the patient is immediately told the truth about the injury. The EMT randomly selected 55 injured patients to immediately tell the truth about the injury and noticed that they averaged 13.1 minutes for their blood to begin clotting after their injury. Their standard deviation was 2.52 minutes. What can be concluded at the the a = 0.10 level of significance? a. For this study, we should use t-test for a population mean b. The null and alternative hypotheses would be: Но: v 13.2 %3D H1: H v > c. The test statistic t v (please show your answer to 3 decimal places.) = d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is s va f. Based on this, we should reject g. Thus, the final conclusion is that ... the null hypothesis. O The data suggest that the population mean is not significantly less than 13.2 at a = 0.10, so there is…

The IQ’s in a certain population are normally distributed with a mean score of 104and a standard deviation of 14. Find the 67th percentile of IQ’s in this population.