Cost of an Operation A medical researcher surveyed 9 hospitals and found that the standard deviation for the cost for removing a person's gall bladder was ss1. Assume the variable is normally distributed. Based on this, find the 95% confidence intervals of the population variance and standard deviation. Round the answers to two decimal places.

After the pandemic hit and people were forced to spend more time indoors, there have been a suspicion among health professionals. that people are eating more and thus gaining weight. In 2018, the average weight of 192 pounds, and health experts want to know if that average weight of the American male has gone up during this pandemic.  d. A sample of 50 American males yeilded a sample average weight of 195 pounds and a sample standard deviation of 14.5 pounds. What is your conclusion at the 5% level of significance? (be sure to state your conclusion in the context of this problem) e. Would your conclusion change if the level of significance were changed to 1%? Briefly explain.

Cereals sodium values have a mean of 167 and a standard deviation of 77.3. Find the z-score for the cereal that has a sodium value of 0. How would you interpret this z-score?

Use the Z-score formula given below Zscore=data - mean            standard deviation It has been determined that the mean task completion times for making fan belts at an auto parts manufacturing facility is 30 minutes. The times are normally distributed with a standard deviation of 2 minutes; a. What percent of belts will take less than 33 minutes to produce? b. What percent of fans will take more than 29 minutes to produce?

Provide an appropriate response.The scores from a state standardized test have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. Use the Empirical Rule to find the percentage of students with scores between 70 and 130. Group of answer choices 95% 68% 99.7% 100%

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Hospital Noise Levels Noise levels at various area urban hospitals were measured in decibels. The mean noise level in  169  ward areas was  60.3  decibels, and the population standard deviation is  6.1 . Find the  96%  confidence interval of the true mean. Use a graphing calculator and round the answers to one decimal place.

Construct a 95​% confidence interval of the population proportion using the given information. x=45, n=150   The lower bound is  The upper bound is

Analysts of traffic control systems believe that the average speed of heavy vehicles on highways has decreased after passing an ordinance of high penalty to regulate over speeding. The average speed for a random selection of 36 trucks was found to be 55 mph with a standard deviation of 5 mph. The speed before the ordinance was passed was an average of up to 57 mph on these highways.Compute the value of the test statistic. Group of answer choices 0.40 -0.40 2.40 -5.37 -2.40