A simple random sample of size n is drawn. The sample mean, x, is found to be 19.2, and the sample standard deviation, s, is found to be 4.2. Click the icon to view the table of areas under the t-distribution. (a) Construct a 95% confidence interval about u if the sample size, n, is 34. ;Upper bound: (Use ascending order. Round to two decimal places as needed.) Lower bound: (b) Construct a 95% confidence interval about u if the sample size, n, is 51. ; Upper bound: (Use ascending order. Round to two decimal places as needed.) Lower bound: How does increasing the sample size affect the margin of error, E? O A. The margin of error decreases. O B. The margin of error does not change. OC. The margin of error increases. (c) Construct a 99% confidence interval about u if the sample size, n, is 34. Lower bound: Upper bound: (Use ascending order. Round to two decimal places as needed.) Compare the results to those obtained in part (a). How does increasing the level of confidence affect the size of the margin of error, E? O A. The margin of error does not change. O B. The margin of error decreases. OC. The margin of error increases.

Assume that adults have IQ scores that are normally distributed with a mean of 100.2 and a standard deviation 20.9. Find the first quartile Q₁, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is (Type an integer or decimal rounded to one decimal place as needed.)

Assume that adults have IQ scores that are normally distributed with a mean of 102.9 and a standard deviation 19.4. Find the first quartile Q,, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is Type an integer or decimal rounded to one decimal place as needed.)

Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal.   Refer to the accompanying data set. Use a 0.05 significance level to test the claim that women and men have the same mean diastolic blood pressure.   a. The test statistic is ​(Round to two decimal places as​ needed.)   b. The​ P-value is ​(Round to three decimal places as​ needed.)

Assume that adults have IQ scores that are normally distributed with a mean of 97.2 and a standard deviation 21.8. Find the first quartile Q₁, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is. (Type an integer or decimal rounded to one decimal place as needed.)

Assume that adults have IQ scores that are normally distributed with a mean of 100.9 and a standard deviation 19.5. Find the first quartile Q1, which is the IQ score separating the bottom 25% from the top 75%. (Hint Draw a graph.) The first quartile is (Type an integer or decimal rounded to one decimal place as needed.)

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1458 and the standard deviation was 312. The test scores of four students selected at random are 1860, 1220, 2150, and 1340. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1860 is (Round to two decimal plaes as needed.)

Assume that adults have IQ scores that are normally distributed with a mean of 103.5 and a standard deviation 24.9. Find the first quartile Q₁, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is (Type an integer or decimal rounded to one decimal place as needed.)

Assume that adults have IQ scores that are normally distributed with a mean of 97.8 and a standard deviation 22.5. Find the first quartile ​Q1, which is the IQ score separating the bottom​ 25% from the top​ 75%. (Hint: Draw a​ graph.)

Assume that adults have IQ scores that are normally distributed with a mean of 100.4 and a standard deviation 23.2. Find the first quartile Q1, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.) The first quartile is: (Type an integer or decimal rounded to one decimal place as needed.)