1) An introductory psychology class has 9 freshman males, 15 freshman females, 8 sophomore males, and 12 sophomore females. If one student is randomly (remember both conditions for a truly random sample) selected from this class, what is the probability of getting a freshman?
A) p = .023
B) p = .455
C) p = .205
D) p = .545
E) p = .341
2) An introductory psychology class has 9 freshman males, 15 freshman females, 8 sophomore males, and 12 sophomore females. A random (remember both conditions for a truly random sample) sample of n = 2 students is selected from the class. If the first student in the sample is a female, what is the probability that the second student will also be a female?
A) p = .386
B) p = .614
C) p = .605
D) p = .341
E) p = .273
3) For a normal distribution, the proportion in the tail beyond z = 1.50 is p = 0.0668. Based on this information, what is the proportion in the tail beyond z = -1.50?
A) p = 0.0668
B) p = -0.0668
C) p = -0.9332
D) p = 0.9332
4) In a normal distribution of grades with a mean of μ = 75 and a standard deviation of σ = 5, what grade separates the lowest 10% of the grades from the rest of the distribution (the 10th percentile)?
A) X = 65
B) X = 59.76
C) X = 68.6
D) X = 85
E) X = 81.4
F) X = -81.4
G) X = -65
5) In a normal distribution of grades with a mean of μ = 75 and a standard deviation of σ = 5, what grade separates the highest 40% of the grades from the rest of the distribution (the 60th percentile)?
A) X = 72
B) X = 76.25
C) X = 73.75
D) X = 35
E) X = 115
F) X = 135.25
6) A normal distribution has a mean of μ = 40 with σ = 4. What is the probability of sampling an individual with a score greater than 44?
A) p = 0.0668
B) p = 0.1587
C) p = 0.8413
D) p = 0.00003
E) p = 0.99997
F) p = 1.00
7) A normal distribution has μ = 100 and σ = 20. What is the probability of randomly selecting a score less than or equal to 130 from this distribution?
A) p = 0.9332
B) p = 0.9032
C) p = 0.0668
D) p = 0.0968
E) p = 1.5
F) p = -1.5
8) In any normal distribution, the middle 50% is bounded by z-scores of ________.
A) z = ± 0.50
B) z = ± 0.67
C) z = ± 0.25
D) z = ± 0.75