Statistics and Probability Answers

If four coins are flipped in succession, then the number of possible outcomes is…………….

a. 8
b. 12
c. 16
d. 14

In a company having 80 employees, 60 earn 10.00 per hour and 20 earn 13.00 per hour. The mean earning per hour is $10.75.

a. $20.15
b. $10.75
c. $10.95
d. $11.78

The grade of student on six examinations were 84, 91, 72, 68, 87, and 78. What is the arithmetic mean of the grades?

a. 88
b. 60
c. 70
d. 80

The scores of 5 students in an examination are: 6, 5, 8, 7 and 4. Find the variance.
a. 3
b. 2
c. 2.5
d. 4.5

During a drug trail for a new antibiotic, 45% of the people who were given the drug experienced dizziness. Assume a sample size of 15 patients..

a) FInd the probability that exactly 8 patients experienced dizziness.

B)FInd the probability that less than 6 patients experienced dizziness.

C)FInd the probability that at least 7 patients experienced dizziness.

D)Find the probability that at most 4 patients did NOT experience dizziness..

Suppose you have a bag containing the following
32 red beads
18 white beads
12 black beads
24 yellow beads
8 pink beads..

Suppose you draw 2 beads out of the bag without replacement. Find the probability of drawing a white bead and then a black bead.

A statistician wishes to test the claim that the standard deviation of the weights of firemen is less than 25 pounds. To do so, she selected a random sample of 20 firemen and found s = 23.2 pounds.

Assuming that the weights of firemen are normally distributed, if the statistician wanted to test her research hypothesis at the .05 level of significance, what is the critical value?

Place your answer, rounded to 3 decimal places, in the blank.

Calculate the variance for the following population. 1,2, 4,6,6,6,8,11,13

Calculate the variance of the following sample. 1,4,8, 9, 9, 10, 14, 18

Find the moment generating function of random variable which is uniformly distributed over (–a, a). Evaluate E (X2n).

Explain the objectives of statistical Average. What are the requisites of a good average?