83 students are asked in a survey how many hours they work during a week. Their responses have a mean of 19 hours and a standard deviation of 2 hours. Find the margin of error for a 80 % confidence interval. Round your answer in two decimal places

In the 2014 MLB season the Los Angeles Dodgers won 94 games and lost 68 to finish in first place in the National League Western Division. Over the 162 games of the regular season they scored an average of 4.43 runs per game, with a standard deviation of 2.88 runs per game. The distribution of their 162 run PERFORMANCES is roughly symmetric, unimodal, and bell-shaped. Dodger Stadium. Photo credit losangeles.dodgers.mlb.com Skete what this distIDUGIONS d mean + 3 SD. n fa a NO wat p In what number of their games would you expect the Dodgers to score fewer than 5.5 runs?

You measure 33 textbooks' weights, and find they have a mean weight of 70 ounces. Assume the population standard deviation is 8.6 ounces. Based on this, construct a 91% confidence interval for the true population mean textbook weight. Round z-values to 2 decimal places; round t-values to 3 decimal places. Round final answers to 2 decimal places. Select an answer

You are given the sample mean and the population standard deviation. Use this information to construct the​ 90% and​ 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals.   From a random sample of 49   business​ days, the mean closing price of a certain stock was ​$109.89 . Assume the population standard deviation is ​$10.27 .

Tina catches a 14-pound bass.  She does not know the population mean or standard deviation.  So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds.  Find the t and calculate a 95% (α = .05) confidence interval.

According to the National Association of Realtors, it took an average of three weeks to sell a home in 2017. Data for the sale of 40 randomly selected homes sold in Greene County, Ohio, in 2017 showed a sample mean of 3.6 weeks with a sample standard deviation of 2 weeks. Conduct a hypothesis test to determine whether the number of weeks until a house sold in Greene County differed from the national average in 2017. Round your answer to four decimal places. p-value = Use a = 0.05 for the level of significance, and state your conclusion. I. Reject Hn. There is a statistically significant difference between the national average time to sell a home and the mean time to sell a home in Greene County. II. Reject Hn. There is not a statistically significant difference between the national average time to sell a home and the mean time to sell a home in Greene County. (II. Do not reject Ho. There is a statistically significant difference between the national average time to sell a home and the…

Construct the confidence interval for the population mean. If the sample size is 35, the sample mean is 4.8, and the sample standard deviation is 2.2. We also know that the population standard deviation is 2.6. Use the Confidence Level = 95%. Use parentheses and four decimal places.

A developmental psychologist is interested in studying how long babies gaze at a photograph of a human face. To test this question, she shows a picture to a sample of six babies and records the length of their gaze in seconds. The data are as follows: 12, 17, 18, 20, 20, 29. Calculate the mean, median, mode, range, variance and standard deviation for the sample.

A Gallup poll wants to determine the mean number of books Americans read each year. How many subjects are needed to estimate the average number of books Americans read with a margin of error of 0.77 books with 95% confidence?Initial results of the Gallup poll indicate that the population standard deviation is 6.2 books.Round your answer up to the next integer.

the population You measure 27 dogs' weights, and find they have a mean weight of 58 ounces. standard deviation is 7 ounces. Based on this, construct a 95% confidence interval for the true population mean dog weight. Give your answers as decimals, to two places - ounces Enter an integer or decimal number [more..]