What is the biggest disadvantage of summarizing the dispersion of a dataset with the variance?
Question 1 options:
The variance is sometimes twice the range.
The variance is always twice the range.
The units are in the original form.
The units are squared.
The value cannot be negative.
The value always contains outliers.
None of these
Under which of the following circumstances would a sample variance be zero?
Question 2 options:
If the mean was zero
If the mean, median and mode were the same number
Variance can never be zero
None of these
If exactly half of the values were above the mean and half below the mean
If all the values in the sample were the same
If the variance of a dataset is correctly computed with the formula using (n 1) in the denominator, which of the following is true?
Question 3 options:
The degrees of freedom will be twice the standard error.
None of these
The variance will be negative.
The dataset is a sample.
The variance will be zero.
The variance is a population parameter.
Which of the following measures of central tendency will always change if a single value in the data changes?
Question 4 options:
None of these
Mode
Mean
Midrange
Variance
Standard deviation
Median
If a positively skewed distribution (right skewed) has a median of 50, which of the following statement is true?
Question 5 options:
None of these
The mean and median are the same
The mode and the median are the same
The variance is negative
The mean is less than 50
The mode is greater than 50
Which of the following variables are not of the ratio level of measurement?
Question 6 options:
Length
None of these
Loudness
Luminosity
Temperature (in Celsius)
Time (in seconds)
Velocity
A grocery store is interested in knowing how many times a typical customer visits in a week. They decide to randomly pick a customer passing through the front door and ask every tenth customer on a specified day to complete a short survey including information about how many times they have visited the store in the past week. What kind of a sampling design is this?
Question 7 options:
None of these
Stratified
Convenience
Multistage
Simple random
Cluster
Suppose that the following tree diagram depicted the results of a survey about the choice of condiment sauces. Based on this diagram, is the probability that a respondent would choose a particular sauce independent of the type of meat? Why or why not?
Tree Diagram
Question 8 options:
They are not independent, because the same sauce is used regardless of the type of meat.
They are independent, because the same sauce is used regardless of the type of meat.
They are not independent, because the sauces have the same probability of being chosen.
They are not independent, because the probability of a sauce is related to the type of meat.
They are independent, because the probabilities are the same regardless of the type of meat.
They are independent, because the sauces have the same probability of being chosen.
Suppose a school sports team has 12 players, of which 10 are taking at least one foreign language class. The school offers only Spanish and French classes. If 8 of the players are taking Spanish and 5 of the players are taking both languages, what is the probability that a random chosen
player from this team is taking French?
Question 9 options:
3/12
10/24
10/12
None of these
7/24
3/10
7/12
What is the probability that, of three randomly selected people, none were born on Monday?
Question 10 options:
1/343
1400/2401
342/343
1/2401
None of these
2400/2401
240/343
Consider the following contingency table for a drug test.
What is the sensitivity of this test?
Question 11 options:
1/5a
2a
75%
3a
None of these
60%
67%
40%
Consider the following contingency table for a drug test.
Which of the following has the highest value?
Question 12 options:
Sensitivity and specificity
Positive predictive value
Negative predictive value and specificity
Positive predictive value and sensitivity
Specificity
Sensitivity
Negative predictive value
None of these
Positive predictive value and specificity
Bag A contains 5 blue marbles and 3 red marbles. Bag 2 contains 4 blue marbles and 6 red marbles. If a bag is selected at random and a ball is drawn from it, what is the probability that the marble is not blue?
Question 13 options:
3/16
6/20
39/40
9/40
124/320
None of these
156/320
Consider the following set of numbers a population.
3 3 5 6 7 12
What is the variance?
Question 14 options:
56/6
56/5
65/6
38/5
None of these
56/5
38/6
For the data depicted in the boxplot below, what is the upper bound for check for outliers?
Question 15 options:
105
97
90
110
None of these
100
95
In the data set below, which of the values are outliers using the Quartile Method?
4, 13, 27, -10, 6, 5, 8, -15, 8, 15, 28, 2
Question 16 options:
-15 and -10
-15, -10 and 28
-15
28
There are no outliers in this data set.
-15 and 28
-15, 27 and 28
27 and 28
Suppose a lie detector machine has an 8% False Negative rate. A group of 100 subjects are asked a sensitive question and one quarter of the subjects decide to lie. From this group, the machine has 75 positive results. What is the specificity of this test?
Question 17 options:
None of these
58.25%
30.67%
45.05%
85.25%
25.25%
39.98%