Question

1.The number of people sick from imported meat products in a certain city was found to be normally distributed with mean and standard deviation: X≈N(U=190, σ =22). What is the probability that the number sick next month in that city would be between 175 and 194?

Select one:

a. 0.3231

b. 0.1803

c. 0.1769

d. 0.6769

2.The number of people getting sick from imported meat products in a certain city in one month was found to be normally distributed with mean and standard deviation :X≈N (u= 190, σ=22). Below what number x, will be found 20 percent of the sick persons (80% of the sick persons will be greater than this number)

Select one:

a. 208.48

b. 171.52

c. 178.56

d. 201.44

3. Suppose there are 75% females and 25% males at UWI (students). This translates to a 75% chance is female is chosen to be the class representative. Suppose there is a 60% chance the class rep gets an A+ for the course. It was noted that there is a 15% chance the class rep gets an A+ for the course and is a male. The events M = male is class rep and A = class rep gets A+ are:

Select one:

a. mutually exclusive events

b. independent events

c. conditional events

d. complementary events

4. Random variable X has cost function 3X + 600. The expected value of X is 20 and the variance of X is 4. What is true about the cost function (expected value and variance)?

Select one:

a. E[3X + 600] = 660                 E[3X + 600] = 36

b. E[3X + 600] = 60                   E[3X + 600] = 636

c. E[3X + 600] = 660                 E[3X + 600] = 12

d. E[3X + 600] = 660                 E[3X + 600] = 636

Answer 1

Mu = 190 sigma = 22 p (175 < times < 194) = p (175 - 190/22 < x - mu/sigma < 194 - 190/22) = p (-15/22 < z < 4/22 = p (-0.68 < z < 0.18) = p (z < 0.180) - p (z < - 0.68) = 0.5714 - 0.2483 = 0.3231 probability = 0.3231