The physical plant at the main campus of a large state university recieves daily requests to replace florecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 54 and a standard deviation of 4. Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 50 and 54? Do not enter the percent symbol. ans = %

Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P42, the 42-percentile. This is the temperature reading separating the bottom 42% from the top 58%. P42 = °C

Find the mean and standard deviation of the following numbers:  35,18,12,32,35,75,32,26,18

Calculate 90th percentile for Z.

A race director is preparing for an upcoming marathon and estimates that the mean time to finish is 315 minutes. Assume that the times are normally distributed, with a standard deviation of 60 minutes. Use this table or the ALEKS calculator to find the percentage of times that are shorter than 453 minutes. For your intermediate computations, use four or more decimal places. Give your final answer to two decimal places (for example 98.23%). % X

A single fair die is rolled seven times. Find the mean and standard deviation of the number of times a 3 appears.

Assume that blood pressure readings are normally distributed with μ= 124 and σ= 9. A researcher wishes to select people for a study but wants to exclude the top and bottom 9 percent. What would be the upper and lower readings to qualify people to participatein the study?

Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P87, the 87-percentile. This is the temperature reading separating the bottom 87% from the top 13%.P87 = °C

Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P50, the 50-percentile. This is the temperature reading separating the bottom 50% from the top 50%. Round to 3 decimal places.