Consider a sample {4, 6, 2, 3, 2}
Find the mean, median, mode, and range
Double points: which measure of center is most affected by extreme values?
Mean = 3.4
Median = 3
Mode = 2
Range = 4
Mean
Draw a mound-shaped graph and label the percentage distributions between 1, 2, and 3 standard deviations from the mean.
Double points: what is this method called?
68%, 95%, 99%
Empirical rule
Draw a scatterplot for the following correlations: strong negative, perfect positive, and no relationship.
Toss a fair coin 3 times. What is the probability of observing at least two tails?
1/2
Toss a coin twice: S = {HH, HT, TH, TT}
Event A: at least one head
Event B: exactly one tail
What is A complement, A intersect B, A union B?
A complement = {TT}
A intersect B = {HT, TH}
A U B = {HH, HT, TH}
Consider a sample {3, 1, 5, 2, 4}
Find the sample variance and standard deviation
Variance = 2.5
Standard deviation = 1.58
Using Tchebysheff’s Theorem, what is the percentage of measurement that will lie within 1, 2, and 3 standard deviations?
0, 75%, 89%
What is the strength and direction for the following values?
r = -0.1
r = 0.6
r = 0
r = -0.1: weak negative linear relationship
r = 0.6: strong positive linear relationship
r = 0: no relationship
Are these mutually exclusive - rolling multiples of 2 and rolling multiples of 3 on dice?
No
A = {2, 4, 6}
B = {3, 6}
At a college, 65% of students took a stats class, 45% took a business class, and 20% of students took both.
What is the percentage of students who have taken neither?
10%
Consider a sample {2, 8, 4, 3, 6} and given s = 2.41
Compute the z-score of 8
Is the score not unusual, somewhat unusual, or an outlier?
Z-score = 1.41
The score is not unusual
Suppose the average test score for an exam is 75 with the standard deviation of 10.
Suppose we know the distribution of the test scores is mound-shaped, what is the proportion of scores between 65 and 85?
Approximately 68%
The following is given: x = {2, 4, 5, 3, 3, 1}, Σx = 18, Σy = 241, and Σxy = 844
Calculate the covariance
24.2
Three M&Ms are drawn one by one in order from a dish containing 6 candies. The total number of simple events is:
120
Given that the student is female, what is the probability that she is colorblind?
2/490
Label the five-number-summary of this box plot
Double points: give the percentages of data within each section
Minimum/lowest value, lower quartile, median, upper quartile, maximum/highest value
25% between each label
Suppose the average test score for an exam is 75 with the standard deviation of 10.
Suppose we do not know the distribution of the test scores, what is the proportion of scores between 55 and 95?
At least 75%
The basic statistics are calculated: sᵪ2 = 3.5, sᵧ2 = 3195.2, and sᵪᵧ = 103.8
Find the correlation coefficient
Indicate the relationship between x and y
0.98
Strong positive relationship
Three members of a 5-person committee must be chosen to form a subcommittee. How many different subcommittees could be formed?
10
Toss a fair coin twice. Define:
A: head on second toss
A complement: tail on second toss
B: head on the first toss
B complement: tail on the first toss
If B occurred, what is the probability that A occurred?
If B didn't occur, what is the probability that A occurred?
Are A and B independent?
1/2
1/2
Yes because the probabilities are the same
Given the five-number-summary of a dataset: 35, 48, 58, 63, 85
What is the percentage of measurements that lie in the inter-quartile-range (from 48 to 63)
What is the percentage that lie between 35 and 63?
50%
75%
Suppose the average test score for an exam is 75 with a standard deviation of 10.
Suppose we know the distribution of the test scores is mound-shaped, what is the proportion of scores between 55 and 85?
Approximately 81.5%
The basic statistics are calculated: x̄ = 2.83, ȳ = 37.5, sᵪ = 1.47, sᵧ = 15.41, and r = 0.9
Find the best fitting regression line
Predict for a family of 5
y = 10.81 + 9.43x
y(5) = 57.96
How many 4-digit lock passwords can we make by using 4 different numbers from 0 to 9?
5040
Suppose 49% of the adult population in a state are female (F).
Also, of the females, 35% have a college degree (C).
A single person is selected at random from the population. What is the probability that the person is a female with a college degree?
.1715