6. Mugs are packed into padded crates for ship- ping. Each crate contains 15 mugs. The mugs are normally distributed with a mean of 450g and a standard deviation of 5g. The weights of the empty crates are also nor- mally distribute with a mean of 150g and a standard deviation of 13g. (a) Calculate the mean and variance for a full crate. (b) 90% of the full crates lie below a certain weight, what is that weight?

Suppose that water usages in American showers are normally distributed, with an average shower using 20 gallons, and a standard deviation of 3.2 gallons. Estimate the percentage of showers that used (a) between 13.6 and 26.4 gallons. % (b) more than 26.4 gallons. % (c) less than 10.4 gallons. % (d) between 16.8 and 29.6 gallons. %

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

Suppose that the quarterly sales levels among health care information systems companies are approximately normally distributed with a mean of 9 million dollars and a standard deviation of 1.4 million dollars. One health care information systems company considers a quarter a "failure" if its sales level that quarter is in the bottom 10% of all quarterly sales levels. Determine the sales level (in millions of dollars) that is the cutoff between quarters that are considered "failures" by that company and quarters that are not. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place.

The chocolate chip cookies that are produced at Perry’s Cookie Emporium have weights which are approximately normally distributed with the mean weight 180 grams and with standard deviations 20 grams. The cookies, however, are sold by count, not by weight. Perry wants to improve his image, so he decides to set aside lightest 20% of the cookies to be packaged and sold separately. What cookie weight will divide the lightest 20% from the heaviest 80%?

This question applies to the next 3 MCQs. Wire wound resistors are being custom made for a Design House with a maximum specification of 305.70 ohms and a minimum specification of 304.55 ohms. If the resistance is higher it can be reworked, if lower they must be scrapped. The resistors manufactured follow a normal distribution with a mean of 305.2 ohms and a standard deviation of 0.25 ohms. What percentage of the resistors are scrap (approximately)? 5% 2% 0.1% 0.5% 1%

Suppose that the quarterly sales levels among health care information systems companies are approximately normally distributed with a mean of 8 million dollars and a standard deviation of 1.3 million dollars. One health care information systems company considers a quarter a "failure" if its sales level that quarter is in the bottom 10% of all quarterly sales levels. Determine the sales level (in millions of dollars) that is the cutoff between quarters that are considered "failures" by that company and quarters that are not. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place. 00 0 million dollars X S ? Check acer Q tab esc ! 1 9. a @ 2 W →> S #m 3 X e C d $ LAS 4 C r % 5 f t > < 6 g y & JX b 7 h C n K1300

times for a surgical procedure are normally distributed. there are two methods. method a has a mean of 29 minutes and a standard deviation of 5 minutes, while method b has a mean of 33 minutes and a standard deviation of 25 minutes. which procedure is preferred if the procedure must be completed within 37 minutes. method a, b, or either method

Researchers wants to determine if low-fat diets or low-carb diets are more effective for weight loss. Suppose 100 people were placed on a low-fat diet and at the end of 3 months the mean weight loss was 10.5 lbs witha standard deviation of 12.5 lbs. There were another 100 people placed on a low-carb diet and at the end of 3 months the mean weight loss was 16.5 lbs with a standard deviation of 10.2 lbs. Does mean weight lossdiffer between the two diets? What are the hypotheses??