3.2
You gather all your quiz scores, add them up, and divide by how many quizzes you took. Boom — you just found what way to describe the “typical” score?
You scored the 40th highest out of 50 students. What percentile are you in?
20th percentile
When interpreting a pie chart, how would you calculate the central angle for a category that represents 18% of the total data?
Multiply 18% by 360 degrees and then divide by 100. (18 × 360)/100 = 64.8 degrees)
In a normal distribution, what percentage of the data lies above the mean and what percentage lies below the mean?
50% above and 50% below
If a z-score of 1.5 corresponds to a data point, what is the probability that a randomly selected data point is less than this value in a standard normal distribution?
approximately 93.32%
Imagine you line up your five favorite snacks by how many calories they have: 4, 7, 9, 12, and 15. Which snack is sitting right in the middle?
9 (the median)
Find the median and the first quartile for this data set:
16, 22, 25, 30, 34, 38, 40, 42, 45
34 and 23.5
Given a stem-and-leaf plot where the stems are tens digits and leaves are ones digits, what value is represented by a stem of 6 and leaves of 2, 7, and 9?
62, 67, and 69
On a normal curve, what percentage of the data falls between the mean and one standard deviation above the mean, according to the Empirical Rule?
34%
Given a data set with a mean of 50 and a standard deviation of 10, what is the z-score for a data point of 60?
1
At a party, a song keeps playing over and over because it’s everyone’s favorite. In a set of numbers, what do we call the number that shows up the most?
Mode
Given the following data set: 12, 15, 18, 21, 24, 30, 36
Find the five-number summary. (List: minimum, Q1, median, Q3, maximum)
12, 15, 21, 30, 36
In the context of a bar graph showing the sales performance of several products, why might it be misleading to use a non-zero baseline for the y-axis?
Using a non-zero baseline exaggerates differences between categories, making minor variations appear more significant than they actually are
If a data set follows a normal distribution, what percentage of the data will fall within three standard deviations of the mean, according to the Empirical Rule?
99.7%
IQ scores have a mean of 100 and a standard deviation of 15. What percentage of IQ scores are between 85 and 115?
approximately 68%
You surveyed your classmates about how many pets they have: 3 students had one pet, 2 students had 2 pets, and 5 students had 3 pets. What is the average number of pets per student? (Round to the nearest whole number)
2 pets per student
A box plot shows that:
• Minimum = 10
• Q1 = 20
• Median = 30
• Q3 = 50
• Maximum = 90
Which part of the data is the most spread out?
The section between Q3 and the maximum
Can the sum of the angles in a pie chart ever exceed 360 degrees?
No, is not possible for the sum of the angles in a pie chart to exceed 360 degrees
The mean of a data set is 120, and the standard deviation is 15. What is the data point that is 2 standard deviations above the mean?
150
In a survey of 200 people, 62% said they prefer online shopping. What is the margin of error for these results? Round to the nearest tenth of a percent.
7.1%
You’re bragging about your grades at lunch:
• Math: A (4.0, 3 credits)
• History: B (3.0, 4 credits)
• English: C (2.0, 3 credits)
• Science: B (3.0, 2 credits)
What’s your GPA?
3.0
You are given a data set:
14, 16, 18, 21, 25, 28, 30, 34, 38, 42, 45, 48, 50, 52, 55
A value of 42 is added to the dataset. How does the insertion of 42 affect the median, Q1, and Q3 of the data set?
The median and Q1 increases, and Q3 slightly decreases
When should you use a histogram instead of a bar graph, and what is the key difference between the two?
You should use a histogram for continuous numerical data and a bar graph for categorical data; the key difference is that histograms have adjacent bars to show intervals, while bar graphs have separated bars for distinct categories.
Given the following data set: 10, 12, 14, 18, 20, calculate the standard deviation. Round to the nearest hundredth.
3.71
In a survey of 250 people, 76% said they support renewable energy initiatives. Find the upper and lower limits for the percent range of supporters. Round to the nearest tenth of a percent.
69.7%-82.3%