Assume that the cholesterol levels among teenagers are Normally distributed with u (mean)= 170 and sigma = 30 mg/dl. What is the probability that the cholesterol level of a teenager is exactly 200 mg/dl? A. 0.8413 B. 0.1587 C. 0  D. 0.5

If z is a standard normal variable, find the probability that z is between -2.07 and 3.28

The time intervals between successive barges passing a certain point on a busy waterway have an exponential distribution with a mean of 12 minutes. a. What is the probability that the time interval between two successive barges will be less than 14.8 minutes?   b. Determine the 77 percentile value for the time interval between two successive barges.

Assume that the traffic to the web site of Smiley's People, Inc., which sells customized T-shirts, follows a normal distribution, with a mean of 4.44 million visitors per day and a standard deviation of 870,000 visitors per day. What is the probability that the web site has 3 million or more visitors in a single day? (Round your answer to four decimal places.)

You sample for carbon monoxide TWA exposure in a work area on 12 randomly chosen days with the following results (in chronological order): 21, 27, 18, 32, 37, 20, 12, 35, 41, 30, 16, 25 ppm a. Using a graphical approach on log-normal probability paper, plot the data and find the GM and GSD. b. Based on the above calculations, what is the probability that on any one day the concentration will exceed 50 ppm?

Assume that the traffic to the web site of Smiley's People, Inc., which sells customized T-shirts, follows a normal distribution, with a mean of 6.5 million visitors per day and a standard deviation of 3 million visitors per day. What is the probability that the web site has more than 1.5 million visitors in a single day? Question 3 options: 0.7545 0.5543 0.9522 0.3454

Assume that the traffic to the web site of Smiley’s People, Inc., which sells customized T-shirts, follows a normal distribution, with a mean of 4.6 million visitors per day and a standard deviation of 880,000 visitors per day. What is the probability that the web site has between 3 million and 4 million visitors in a single day? If needed, round your answer to four decimal digits.

Lost-time accidents occur in a company at a mean rate of 0.3 per day. Using the data  above, what is the probability that the number of lost-time accidents occurring over a period of 7 days will be more than 3?

The level of nitrogen oxides (NOX) and nonmethane organic gas (NMOG) in the exhaust over the useful life (150,000150,000 miles of driving) of cars of a particular model varies Normally with mean 8080 mg/mi and standard deviation 66 mg/mi. A company has 1616 cars of this model in its fleet. Using Table A, find the level ?L such that the probability that the average NOX + NMOG level ?¯x¯ for the fleet greater than ?L is only 0.030.03 ? (Enter your answer rounded to three decimal places. If you are using CrunchIt, adjust the default precision under Preferences as necessary. See the instructional video on how to adjust precision settings.)

On average, a banana will last 6.1 days from the time it is purchased in the store to the time it is too rotten to eat. Is the mean time to spoil greater if the banana is hung from the ceiling? The data show results of an experiment with 12 bananas that are hung from the ceiling. Assume that that distribution of the population is normal. 5.5, 6.6, 5.1, 8.4, 7.1, 5.1, 4.8, 5.1, 8.1, 5.4, 7, 7.8 What can be concluded at the the a = 0.05 level of significance level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: ? Select an answer ✓ H₁: ? Select an answer ✓ 4 c. The test statistic?v= (please show your answer to 3 decimal places.) (Please show your answer to 4 decimal places.) d. The p-value =