STAB22H3 Study Guide - Midterm Guide: Random Variable, Box Plot, Scatter Plot
Question 1
Who: the comparison is done about 10 infant car seats
What: they have considered about brand, cost, age limit, weight limit, and overall
safety rating.
Why: This has been done to provide information to the readers of the magazine.
Answer: D
Question 2
Percentage of the members who chose Tennis as their favorite sport
= 100 −(45 +10 +22)
=23%
∴ Number of members who chose Tennis as their favorite sport = 23% ∗400 =92
Answer: B
Question 3
In the histograms it depicted that the homicides from strangulation has increased over
time instead of decreasing.
Answer: C
Question 4
Step 1
According to the given histogram it is a left skewed distribution
Step 2
In a left skewed distribution < <
Median will be a more appropriate central tendency measure than mean when outliers
are exist.
In this case it is not, therefore mean will be the most appropriate central tendency
measure in this situation.
Answer: C
Question 5
=(+ 1)
2ℎ =(28 + 1)
2ℎ =14.5ℎ
There are even number of observations (n = 28) in the data set. Therefore there are two
middle values, after it’s arranged in ascending or descending order. Median is the mean
of those two middle values
=17 +17
2=17
Answer: D
Question 6
=3−1
60 = 3−27
3=87
Answer: C
Question 7
Let X be a random variable
= ℎ ℎ
= −
1.20 =−100
15
= 1.20 ∗15 +120 =118
Answer: E
Question 8
According to the box plot this is a left skewed distribution
The median is 68 years not the mean
=3−1=69 −66 = 3
As an example:
Answer: C
Question 9
Categorical variables:
X1 = Type of car the student owns
X4 = Home state (or province) of the student
Answer: C
Question 10
Median, 1st quartile, 3rd quartile, and IQR are not affected by the outliers since they
depend only on the sample size (number of data points). The above measures are
independent from the individual data points.
But standard deviation depends on the individual data points, therefore it is affected
mostly by the outliers.
Answer: D
38
STAB22H3 Full Course Notes
Verified Note
38 documents
