3- A previous analysis of paper boxes showed that the standard deviation of their lengths is 9 millimeters. A packer wishes to find the 96% confidence interval for the average length of a box. How many boxes does he need to measure to be accurate within 3 millimeters?

I need the answers ,b, c , d, f , g Thank you

we want to obtain a sample to estimate a population mean. Based on previous evidence, researchers believe the population standard deviation is approximately 38.7. We would like to be 99% confident that the estimate is within 4 of the true population mean. How large of a sample size is required ?

Previous Question Researchers measured the data speeds for a particular smartphone carier at 50 airports. The highest speed measured was T76 Mbps. The complete list of 50 data speeds has a mean of x 17.47 Mbps and a standard deviation of s 32.99 Mbps. a. What is the dilference between camer's highest data speed and the mean of all 50 data speeds? b. How many standard deviations is that (the difference found in part (a)? c Convert the camer's highest data speed to az score. d. If we consider data speeds that convert to z scores between-2 and 2 to be neither significantly low nor significantly high, is the camier's highest data speed significant? a. The difference is Mbps (Type an integer or a decimal Do not round) b. The dilference is standard deviations (Round to two decimal places as needed.) c The z score is z (Round to two decimal places as needed.) d. The camer's highest data speed is

To compare the dry braking distances from 30 to 0 miles per hour for two makes of automobiles, a safety engineer conducts braking tests for 35 models of Make A and 35 models of Make B. The mean braking distance for Make A is 42 feet. Assume the population standard deviation is 4.7 feet. The mean braking distance for Make B is 45 feet. Assume the population standard deviation is 4.4 feet. At a = 0.10, can the engineer support the claim that the mean braking distances are different for the two makes of automobiles? Assume the samples are random and independent, and the populations are normally distributed. Complete parts (a) rari rz (b) Find the critical value(s) and identify the rejection region(s). The critical value(s) is/are (Round to three decimal places as needed. Use a comma to separate answers as needed.)

1. A recent study of 22 motorists showed that they spent an average of P750 per week. The standard deviation of the sample was P90. Find the 99% confidence interval of the true mean. Solution: 2. A sample of 15 National Collegiate Athletics Association (NCAA) basketball players had an average height of 6 feet with a sample standard deviation of 0.80 foot. Find the 90% confidence interval of the true mean height of all players. Solution:

on is 3. Give the 5. A randomly selected 80 scores from the scores of the students enrolled in a Statistics class that is normally distributed with a standard deviation of 10 have a sample mean of 85. a. Find the margin of error if the confidence level is 90%. b. Give the 98% confidence interval for the entire scores of the students in the Statistics class.

In one of the Stat 2 sections, the students in the section have an average height of 64 inches, with a standard deviation of 3 inches. The GSI happens to be 68 inches. Express the height of the GSI in standard units, relative to the students in the section. Choose the answer below that is closest. Group of answer choices 1.67 3.0 1.5 1.33 4.0      PreviousNext

Suppose an interval estimate for the population mean was 62.84 to 69.46. The population standard deviation was assumed to be 6.50, and a sample of 100 observations was used. The mean of the sample was:

Solve this problem to find the sample standard deviation