Practice the questions of McGraw Hill Math Grade 8 Answer Key PDF Unit Test Lessons 23–24 to secure good marks & knowledge in the exams.
McGraw-Hill Math Grade 8 Unit Test Lessons 23–24 Answer Key
Question 1.
What is the probability of:
Spinning an odd number? ________________
Spinning a 2? ________________
Spinning either a 2 or 4? ________________
Spinning a 1? ________________
Answer:
Spinning an odd number is \(\frac{6}{12}\);
Spinning a 2 is \(\frac{1}{6}\);
Spinning either a 2 or 4 \(\frac{5}{12}\);
Spinning a 1 \(\frac{1}{6}\).
Explanation:
Total event on the spinning wheel,
[1, 2, 4, 5, 2, 3,7, 6, 4, 4, 1, 3]
and the total possible events on the spinning wheel is 12.
all positive events = [2, 2, 4, 4, 4, 6]
all negative events = [1, 1, 3, 3, 5, 7]
Spinning an odd number is \(\frac{6}{12}\)
Spinning an odd number is \(\frac{1}{2}\)
Total event on the spinning wheel,
[1, 2, 4, 5, 2, 3,7, 6, 4, 4, 1, 3]
Spinning a 2 is \(\frac{2}{12}\)
\(\frac{1}{6}\)
Spinning either a 2 or 4,
[2, 2 and 4, 4, 4] total 5 events.
\(\frac{2+3}{12}\)
\(\frac{5}{12}\)
Spinning a 1 = \(\frac{2}{12}\)
= \(\frac{1}{6}\)
Question 2.
What is the range of the data? ________________
What is the median of the data? ________________
What is the mean of the data? ________________
Answer:
The range of the data is 49;
The median of the data 67;
The mean of the data 67.5.
Explanation:
In the above given stem and leaf diagram,
the starting point is 45 and the ending point or number is 94.
The difference between the ending number – starting number is range.
Range = 94 – 45 = 49
The range of the data is 49.
[45, 46, 56, 58, 61, 67, 72, 77, 78, 89, 94]
The median of the data 67.
The median is the middle number in a sorted,
ascending or descending list of numbers can be more descriptive of the data set than the average.
Mean is the average number by adding all data points and dividing by the number of data points.
Mean = [45 + 46 + 56 + 58 + 61 + 67 + 72 + 77 + 78 + 89 + 94]/11
Mean = 743/11 = 67.5
The mean of the data 67.5
Question 3.
How many different combinations of outfits can be created from the choices? ________________
How many possibilities are there that include green-striped shirts? ________________
How many possibilities are there that include a yellow tie and gray pants? ________________
Answer:
27 different combinations of outfits can be created from the choices.
9 possibilities are there that include green-striped shirts.
3 possibilities are there that include a yellow tie and gray pants.
Explanation:
If an event can occur in ‘m’ different ways following,
which another event can occur in ‘n’ different ways,
following which a third event can occur in ‘p’ different ways.
The total number of occurrence to the events in the given order is m x n x p.
3 Ties,
3 Pants,
3 Shirts,
3 x 3 x 3 = 27
27 different combinations of outfits can be created from the choices.
9 possibilities are there that include green-striped shirts.
3 x 3 = 9
3 possibilities are there that include a yellow tie and gray pants.
1 x 3 = 3
Question 4.
What is the median of this data plot? ________________
What is the range of the data? ________________
Answer:
The median of this data plot is 6.
The range of the data 1.5,
Explanation:
Range of the data = Max – Min
Range = 6.5 – 5 = 1.5
Median on the box plot is the middle point =6.0
Question 5.
Students in James’s health class were polled on their favorite health food snack. The results are displayed on the graph.
What is the least favorite health food snack? ________________
What is the favorite health food snack? ________________
How many more people preferred carrots to cauliflower? ________________
Answer:
The least favorite health food snack is Broccoli;
The favorite health food snack is Hummus;
7 more people preferred carrots to cauliflower.
Explanation:
Students in James’s health class were polled on their favorite health food snack.
The results displayed on the above graph tells that,
only 4 of the students preferred Broccoli,
14 students that is majority of them like Hummus,
and 7 more people preferred carrots to cauliflower.
Question 6.
Janice was making a schedule to determine how many volunteers she needed for the nature center guided tours. She charted the number of visitors to the nature center during the prior summer.
What month had the most visitors? ________________
What month had the fewest visitors? ________________
During what months should Janice increase her staffing to meet the demand for guided tours? ________________
Answer:
July month had the most visitors.
September month had the fewest visitors.
During July to august months Janice increase her staffing to meet the demand for guided tours.
Explanation:
Janice charted the number of visitors to the nature center during the prior summer.
As she was making a schedule to determine number of volunteers needed for the nature center guided tours.
According to the given chart in July month number of visitors are more and,
in September month number of visitors are less.
During July to August months Janice need to increase her staffing to meet the demand for guided tours.
Question 7.
Peggy charted bike rentals for the previous month. What was the most popular kind of bike rented?
Which kind of bike speed was the least popular?
Answer:
The most popular kind of bike rented is 12 speed.
3 speed bike was the least popular.
Explanation:
Peggy charted bike rentals for the previous month.
From the above pie chart,
12 speed bike is the most popular kind of bike rented and,
3 speed bike was the least popular.
Question 8.
Coach Taylor made a chart of the performance of his two best hitters. In which month did Langely hit more extra base hits than Stanton?
How many more extra base hits did Stanton have than Langely in the month of September?
Answer:
In June month Langely hit more extra base hits than Stanton.
5 more extra base hits Stanton than Langely in the month of September.
Explanation:
Coach Taylor made a chart of the performance of his two best hitters.
From the above chart given,
June is the month where Langely hit more extra base hits than Stanton.
In the month of September 5 more extra base hits Stanton than Langely.
Question 9.
Use the Venn Diagram to display the following data: 25 students take Algebra I, 22 students take US History, and 8 students take both courses.
Answer:
Explanation:
25 students take Algebra I,
22 students take US History,
8 students take both courses.
Number students in Algebra I = 25 – 8 = 17
Number students in U.S. History = 22 – 8 = 14.