Question

1- If two patients undergone a medical treatment with a success rate of 85%, assuming the results are independents for the two patients. What is the probability that neither one of the two patients will benefit from the treatment

A. 0.7225

B. 0.0225

C. 0.1275

D. 0.1260

2- Maple tree diameter in a forest is normally distributed with a mean of 10 inches and a standard deviation of 2.2 inches. Which interval contain the middle 95%

A. (7.8,12.2)

B. (3.4,16.6)
C. (5.6,14.4)

D. (7.8,14.4)

3- Pulse rates of adult men are normally distributed with a mean of 70 and a standard deviation of 8. What is the probability that a randomly selected man with a pulse rate greater than 76

A. 0.7734

B. 0.2266

C. 0.2734

D. 0.5468

4- For hypothesis test about a mean, you should use a sample size greater than 30 when

A. the population distribution is not normal

B. the p-value is less than α

C. the population size is large

D. the significance level is greater than 1

5- If the coefficient of determination is equal to 1 then the correlation coefficient

A. must be equal to 1

B. can be either -1 or +1

C. can be between -1 and +1

D. must be -1

Answer 1

1.

If two patients have undergone a medical treatment with a success rate of 85%, assuming the results are independents for the two patients. What is the probability that neither one of the two patients will benefit from the treatment

P(success) = 0.85

P(not success) = 0.15.

The probability that neither one of the two patients will benefit from the treatment is 0.15 * 0.15 = 0.0225

.

.

2.

Maple tree diameter in a forest is normally distributed with a mean of 10 inches and a standard deviation of 2.2 inches.

n = 1

.

.

3.

Pulse rates of adult men are normally distributed with a mean of 70 and a standard deviation of 8.

We need to compute Pr(X≥76). The corresponding z-value needed to be computed is:

Therefore, we get that

The probability that a randomly selected man with a pulse rate greater than 76 is 0.2266.

.

.

4- For hypothesis test about a mean, you should use a sample size greater than 30 when the population distribution is not normal.

.

.

5- If the coefficient of determination is equal to 1 then the correlation coefficient can be either -1 or +1.