Math Answers

"An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed, with mean equal to 984 hours and a standard deviation of 52 hours. Random samples of 41 bulbs are drawn from this population, and the mean of each sample is determined. What is the mean of the mean of the sampling distribution?""An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed, with mean equal to 984 hours and a standard deviation of 52 hours. Random samples of 41 bulbs are drawn from this population, and the mean of each sample is determined. What is the mean of the mean of the sampling distribution?"

"The water bills for residents in Davao City have a mean of Php2085 and a standard deviation of Php129. Random samples of 86 water bills are drawn from this population, and the mean of each sample is determined. What is the mean of the mean of the sampling distribution."

determine if the following are probability distribution (if no, state why)

X=1,2,3,4 and 5

P(x)= 3/10, 1/10, 1/10, 2/10 and 3/10

Solve the following measurements:

a. On a certain map, the straight-line distance between The Pas and Winnipeg is 4.1cm. If the scale of the map is 1cm = 120km, how far apart are The Pas and Winnipeg, to the nearest kilometre?

b. On a scale drawing of a house, the scale is 1cm: 4m. If the actual width of the house is 30m, what is the length of the line in the drawing that represents the width of the house?

c. If an electronics company wants to shrink the dimensions of a Tablet measuring 20cm wide by 25cm high by a scale factor of 2/5, what is the new width of the Tablet? (Recall that the Scale Factor is given by either model/original OR model:original.)

(Need to show work)

it is reported that 72% of the working women use computers at work. Choose 5 women at random and find the probability that at least 1 doesn't use a computer at work

The mean annual cost of car insurance is Rs 9450 and standard deviation of Rs 250. What is the probability that the average insurance cost of a sample of 25 cars will be between Rs 9400 and Rs 9500?

f(z)= z/(z+1)(z+1)^2

1. To the left of z= -1.66

2.to the left of z=1.47

3.to the right of z=2.52

4.to the right of z= -1.75

5.between z=1.5 and 2.76

Determine if the following are probability distributions (if no, state why)

x= {3,6,9,12,15}

p(x)= {4/9,2/9,1/9,1/9,1/9}

According to the article "A Critical Appraisal of 98.6 Degrees F, the Upper Limit of the Normal Body Temperature, and Other Legacies of Carl Reinhold August Wunderlich" published in the Journal of the American Medical Association, the body temperatures of adults are normally distributed with a mean of 98.261 and a standard deviation of 0.733.

1. What is the probability that a randomly selected person's body temperature is between 98.02 and 98.53? Round your answer to 4 decimal places.
2. What is the probability that the average body temperature of 7 randomly selected people is between 98.02 and 98.53? Round your answer to 4 decimal places.