Introduction to Statistics Unit 2 Milestone 2 Exam
Choose the statement that correctly describes a normal distribution.
Approximately 68% of the values lie within one standard deviation of the mean.
The approximate percent of values lying within three standard deviations of the mean is 49.85%.
The approximate percent of values lying within two standard deviations of the mean is 47.5%.
Approximately 68% of the values are greater than the mean value.
In a poll of 300 preschoolers, 125 said they preferred chocolate ice cream, 71 said they preferred vanilla, 100 said they preferred cookies & cream, and 4 said they had never eaten ice cream.
If a pie chart were to be made showing the preference for each flavor, the central angle for the chocolate ice cream sector would be __________.
In a survey to rate the pizzas served by a pizza parlor, 250 people rated their agreement with the statement, “The pizzas here are one of the best I’ve ever had.” The answers were put into a table.
The relative frequency of people who strongly agree with the statement is __________.
Ralph records the time it takes for each of his classmates to run around the track one time. As he analyzes the data on the graph, he locates the mean and median time.
Which component of data analysis is Ralph utilizing?
- The overall shape of the data
An outlier in the data set
The center of the data set
The overall spread of the data
Naomi weighed 50 patients for a medical study using a scale that measures to the nearest whole pound. She then calculated the mean weight as 176 pounds, with a standard deviation of 12 pounds.
If the distribution is normal, what percent of the data lies between 140 pounds and 212 pounds?
Katherine, Jonathan, and Ryan went bowling. Afterwards, two of them decided to make bar graphs to plot their scores. Who made Graph 2, and why?
In which of these cases should mode be used?
When the data is represented using interval scale
When the data is qualitative and we talk about the most frequent category
When the data is represented using ratio scale
When the data has extreme values
A baseball scout recorded the type of pitch a pitcher threw during a game and whether it was thrown for a strike or a ball.
Which of the following statements about the stack plot is true?
The pitcher threw the changeup the most often.
The pitcher threw the curveball most often.
The weekly salaries of full-time and part-time employees at a company are listed on the table.
What does the circled section represent?
Nick just received his test back. He scored a 24 out of a possible 60 points. His teacher told him the mean score on the test was a 35, with a standard deviation of 6.
What is Nick’s z-score?
The difference between the standard deviation and the variance of a standard normal distribution is __________.
Which of the following statements about a negatively skewed distribution is true?
The formula for the standard deviation of a sample is:
Select the true statement for the following data set that has a mean of 9:
3, 7, 8, 8, 8, 9, 10, 10, 13, 14
Answer choices are rounded to the hundredths place.
The variance is 8.50 and the standard deviation is 3.09.
The variance is 3.09 and the standard deviation is 9.56.
The graph in the figure shows the change in the Consumer Price Index over an 11-year period.
Which segment of the graph indicates no change in the Consumer Price Index?
Let x stand for the length of an individual screw. 100 screws were sampled at a time. The population mean is 2.5 inches and the population standard deviation is 0.2 inches.
What is the mean of the sampling distribution of sample means?
The third quartile (Q3) value from this box plot is __________.
Sara wonders what percentage of her students answered at least half of the quiz questions incorrectly.
The relative cumulative frequency of students who earned a score of 21 or higher on the quiz is __________.
At Brent’s school, the final grade for his U.S. History course is weighted as follows:
- Tests: 30%
- Quizzes: 50%
- Homework: 20%
Brent has an average of 82% on his tests, 94% on his quizzes, and 50% on his homework.
What is Brent’s weighted average?
Dave drives to work. While driving the car over nine days, he observes his daily average speed and lists it in the table below.
The median speed at which Dave drove to work was __________.
Adam graded ten standardized tests with the following scores:
48, 65, 72, 86, 84, 52, 93, 97, 81, 80
Which standardized test score represents the 70th percentile?
Consider the histogram showing the heights of individuals on a basketball team.
How many players are taller than 78 inches?