Question 1 of 25
An advertisement for a car states that it is 10% more powerful than its competitor. This is an example of
A. detached statistics
B. changing the subject
C. ambiguous averages
D. suspect samples Reset Selection
Part 2 of 9 -
Question 2 of 25
If A and B are any two events with P(A) = .8 and f$P(B|ar{A})= .7f$ then f$P(ar{A}igcap{B})f$ is:
A. 0.56
B. 0.875
C. 0.14
D. .24
Question 4 of 25
Find the variance of the following probability distribution.
X P(X)
1 0.20
2 0.15
3 0.25
4 0.25
5 0.15
A. 1.34
B. 1.8
C. 0.48
D. 1.16
Question 5 of 25
We assume that the outcomes of successive trials in a binomial experiment are:
A. random numbers between 0 and 1
B. probabilistically independent
C. identical from trial to trial
D. probabilistically dependent Reset Selection
Question 6 of 25
One of the requirements for a binomial experiment is that there must be a(n) _____ number of trials.
A. odd
B. random
C. fixed
D. infinite
Question 9 of 25
If Z is a standard normal random variable, then the value z for which P(-z < Z < z) equals 0.8764 is
A. 0.3764
B. 1.54
C. 1.16
D. 3.08
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Question 10 of 25
In a normal distribution, changing the standard deviation:
A. makes the curve more or less spread out
B. makes the curve more robust
C. splits the distribution to two curves
D. shifts the curve left or right
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Question 11 of 25
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
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 student scored 84 points on a test where the mean score was 79 and the standard deviation was 4. Find the student's z
score, rounded to 2 decimal places, and place it in the blank.
Part 6 of 9 -
Question 14 of 25
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.
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
6
P (X=x)
0.55
0.15
0.10
0.10
0.04
0.03
0.03
Find P(1 < X < 5). Place your answer, rounded to two decimal places in the blank. For example, 0.56 would be a legitimate entry.
Question 15 of 25
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.
Suppose that the probability that a new medication will cause a bad side effect is 0.03. If this medication is given to 150 people, what is the probability that exactly three of them will experience a bad side effect?
Place your answer, rounded to 4 decimal places, in the blank.
Part 7 of 9 -
Question 16 of 25
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.
If a set of six books is to be placed on a shelf, in how many ways can the six books be arranged? Place your answer in the blank.
Do not use any decimal places or commas. For example, 45 would be a legitimate entry.
Question 17 of 25
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.
The president of a bank is attempting to arrange a meeting with the three vice presidents for a Friday weekly meeting. He
believes that each of these three busy individuals, independently of the others, has about 40% chance of being able to attend
the meeting. What is the probability that at least two of the three vice presidents can attend the meeting? Place your answer,
rounded to 3 decimal places, in the blank. For example, 0.123 would be a legitimate entry.
Part 8 of 9 -
Question 18 of 25
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.
Mrs. Smith's reading class can read a mean of 175 words per minute with a standard deviation of 20 words per minute. The top
3% of the class is to receive a special award.
Assuming that the distribution of words read per minute are normally distributed, what is the minimum number of words per minute a student would have to read in order to get the award? Place your answer, rounded to the nearest whole number, in the blank.
When entering your answer do not use any labels or symbols. Simply provide the numerical value. For example, 123 would be a legitimate entry.
Question 19 of 25
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.
Suppose that the average weekly earnings for employees in general automotive repair shops is $450, and that the standard deviation for the weekly earnings for such employees is $50.
A sample of 100 such employees is selected at random.
Find the probability that the mean of the sample is greater than $460.
Place your answer, rounded to 4 decimal places, in the blank. For example, 0.2345 would be a legitimate answer.
Question 20 of 25
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 popular retail store knows that the purchase amounts by its customers is a random variable that follows a normal distribution with a mean of $30 and a standard deviation of $9.
What is the probability that a randomly selected customer will spend less than $15 at this store?
Place your answer, rounded to 4 decimal places, in the blank. For example, 0.3456 would be a legitimate entry.
Question 21 of 25
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 set of final exam scores in an organic chemistry course was found to be normally distributed, with a mean of 73 and a standard deviation of 8.
What is the probability of getting a score higher than 71 on this exam? Place your answer, rounded to 4 decimal places in the blank. For example, 0.3456 would be a legitimate entry.
Question 22 of 25
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.
It has been observed that electrical connectors manufactured by Jolt Electrical Supply Company last an average of 18.2 months and follow a normal distribution with a standard deviation of 1.7 months. Jolt agrees to replace any connector that fails within 19 months.
Out of 500 connectors sold, how many does Jolt expect to replace, on average?
Place your answer, rounded to the nearest whole number, in the blank. For example, 123 would be a legitimate answer.
Question 23 of 25
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.
Scores on a mathematics examination appear to follow a normal distribution with mean of 65 and standard deviation of 15.
The instructor wishes to give a grade of "C" to students scoring between the 60th and 70th percentiles on the exam.
What score represents the 60th percentile score on the mathematics exam?
Place your answer in the blank, rounded to a whole number. For example, 62 would be a legitimate entry.
Part 9 of 9 -
Question 24 of 25
Using the standard normal curve, the Z- score representing the 75th percentile is approximately 0.674.
True
False
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Question 25 of 25
The left half under the normal curve is slightly smaller than the right half.
True
False