the tensil strength of spot welds produced by a robot welder is approximately normally distributed, with a mean of 10,000 pounds per inch and a standard deviation of 800 pounds per inch. For a simple random samply of forty welds determine:   the probability that the sample mean will be at least 10,200 pounds per square inch the probability that the sample mean will be less than 9,900 pounds per square inch the probability that the sample mean will be between 9,700 pounds per square inch and 10,300 pounds per square inch

A ski gondola carries skiers to the top of a mountain. Assume that weights of skiers are normally distributed with a mean of 186 lb and a standard deviation of 44lb. The gondola has a stated capacity of 25 ​passengers, and the gondola is rated for a load limit of 3500lb. Complete parts​ (a) through​ (d) below. A. Given that the gondola is rated for a load limit of 3500​lb, what is the maximum mean weight of the passengers if the gondola is filled to the stated capacity of 25 ​passengers? The maximum mean weight is______ B.  If the gondola is filled with 25 randomly selected​ skiers, what is the probability that their mean weight exceeds the value from part​ (a)? The probability is____ C. If the weight assumptions were revised so that the new capacity became 20 passengers and the gondola is filled with 20 randomly selected​ skiers, what is the probability that their mean weight exceeds 186 ​lb, which is the maximum mean weight that does not cause the total load to exceed 3500​lb? The…

Scores of each of the Knitting Aptitude tests were normally distributed with a mean of 6 hours and a standard deviation of 1.67 hours. Carrie will be taking the test tomorrow. Assume the data is normally distributed. Determine the probability of someone finishing in less than 2.17 hours 0.9891 0.5000 1.0 0.0109

A car company says that the mean gas mileage for its luxury sedan is at least 22 miles per gallon​ (mpg). You believe the claim is incorrect and find that a random sample of 6 cars has a mean gas mileage of 21 mpg and a standard deviation of 2 mpg. At α=0.10​, test the​ company's claim. Assume the population is normally distributed. Click here to view the t-distribution table. LOADING... Click here to view page 1 of the normal table. LOADING... Click here to view page 2 of the normal table. LOADING... Which sampling distribution should be used and​ why?     A. Use a normal sampling distribution because the population is​ normal, and σ is known.   B. Use a​ t-sampling distribution because the population is​ normal, and σ is known.   C. Use a normal sampling distribution because the population is​ normal, and σ is unknown.   D. Use a​ t-sampling distribution because n<30.   E. Use a normal sampling distribution because n>30.   F. Use a​…

A vending machine pours soda into a cup. The cup has a capacity of 300 mL (the amount of fluid that it can hold without overflowing.) The machine is set to pour an average of 250 mL into a cup, and pours are normally distributed. What value should the standard deviation have in order than no cups will overflow?

A car company says that the mean gas mileage for its luxury sedan is at least 23 miles per gallon​ (mpg). You believe the claim is incorrect and find that a random sample of 7 cars has a mean gas mileage of 22 mpg and a standard deviation of 3 mpg. At α=0.10​, test the​ company's claim. Assume the population is normally distributed. Click here to view the t-distribution table. LOADING... Click here to view page 1 of the normal table. LOADING... Click here to view page 2 of the normal table. LOADING... Which sampling distribution should be used and​ why?     A. Use a normal sampling distribution because the population is​ normal, and σ is unknown.   B. Use a​ t-sampling distribution because the population is​ normal, and σ is unknown.   C. Use a normal sampling distribution because the population is​ normal, and σ is known.   D. Use a​ t-sampling distribution because n<30.   E. Use a​ t-sampling distribution because the population is​ normal, and σ is…

Compute the range and sample standard deviation for strength of the concrete​ (in psi). 3910​, 4090​, 3500​, 3100​, 2940​, 3830​, 4090​, 4040

Assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. Draw a graph and find the probability of a bone density test score between negative 1.62 and 1.62.   The probability is ​(Round to four decimal places as​ needed.)

Assume all populations are normally distributed. A travel analyst claims that the mean price of a round trip flight from New York City to Los Angeles is less than $507. In a random sample of 55 round trip flights from NYC to LA, the mean price is $502. Assume the population standard deviation is $111. At α = 0.05, is there enough evidence to support the travel analyst’s claim?

I. NORMAL PROBABILITY DISTRIBUTION Cars are passing through a checkpoint. Assume the speeds are normally distributed such that the mean (u) = 61 mph and the standard deviation (sigma) = 4 mph. а. b. Calculate the probability (area under the curve) that the next car to pass will be travelling more than 58 mph.