MATH 302
STATISTICS: NUMERICAL ANALYSIS
MIDTERM QUIZ
A histogram that is positively skewed is also called A.symmetric
B.skewed to the right
... [Show More] C.balanced D.skewed to the left
Answer Key: B
Part 2 of 9 - 2.0/ 2.0 Points
Question 2 of 25 1.0/ 1.0 Points
In a genetics experiment 5 flowers out of 8 were bicolor, and the rest were solid color. If 3 of the flowers are selected at random without replacement, what is the probability that all 3 are bicolor?
A.0.1786 B.0.2441 C.0.375 D.0.625
Answer Key: A
Question 3 of 25 1.0/ 1.0 Points
If a die is rolled one time, find the probability of getting a number greater than 2.
A.2 B.-1 C.5/6 D.4/6
Part 3 of 9 - 1.0/ 3.0 Points
Question 4 of 25 0.0/ 1.0 Points
The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.
x
0
1
2
3
4
5
P (X=x)
0.20
0.25
0.20
0.15
0.10
0.10
What is the expected value of X?
A.1.20
B.2.0
C.3.65
D.6.25
Answer Key: B
Question 5 of 25 0.0/ 1.0 Points
Which term is NOT synonymous with the expected value of a discrete probability distribution?
A.variance B.μ
C.theoretical average D.mean
Answer Key: A
Feedback: All of the terms except for "variance" refer to the mean or expected value of a discrete probability distribution.
Question 6 of 25 1.0/ 1.0 Points
In one town 33% of the households have a vehicle with all-wheel drive. If 4 households are selected at
A.0.0825 B.0.4662 C.0.33 D.0.0119
Answer Key: D
Part 4 of 9 - 5.0/ 6.0 Points
Question 7 of 25 1.0/ 1.0 Points
Given that Z is a standard normal variable, the value z for which P(Z < z) = 0.2580 is A.-0.65
B.0.758 C.0.242 D.-0.70
Answer Key: A
Question 8 of 25 1.0/ 1.0 Points
Given that Z is a standard normal random variable, P(-1.0 < Z < 1.5) is A.0.0919
B.0.8413 C.0.9332 D.0.7745
Answer Key: D
Question 9 of 25 0.0/ 1.0 Points
The normal distribution is:
A.a density function of a discrete random variable
B.a binomial distribution with only one parameter
C.a discrete distribution
D.the single most important distribution in statistics
Answer Key: D
Question 10 of 25 1.0/ 1.0 Points
The standard deviation of a probability distribution is a: A.measure of central location
B. measure of relative likelihood
C. measure of skewness of the distribution
D. measure of variability of the distribution
Answer Key: D
Question 11 of 25 1.0/ 1.0 Points
The average height of flowering cherry trees in a nursery is 11 feet. If the heights are normally distributed with a standard deviation of 1.6, find the probability that a randomly selected cherry tree in this nursery is less than 13 feet tall.
A. 0.67
B.0.89
C.0.95
D.0.11
Answer Key: B
Question 12 of 25 1.0/ 1.0 Points
The standard deviation of a probability distribution must be:
A.a negative number
B.a nonnegative number
C.less than the value of the mean
D.a number between 0 and 1
Answer Key: B
Part 5 of 9 - 1.0/ 1.0 Points
Question 13 of 25 1.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A statistics professor has just given a final examination in his statistical inference course. He is particularly interested in learning how his class of 40 students performed on this exam. The scores are shown below.
77 81 74 77 79 73 80 85 86 73
83 84 81 73 75 91 76 77 95 76
90 85 92 84 81 64 75 90 78 78
82 78 86 86 82 70 76 78 72 93
What is the median score on this exam? Place your answer, rounded to two decimal places in the blank. For example, 65.78 would be a legitimate entry. 79.5
Answer Key: 79.50
Part 6 of 9 - 2.0/ 2.0 Points [Show Less]