Which method of gathering data will be most effective in learning how diet and fitness choices affect long-term health?
an observational method
A random number generator is used to model the patterns of animals in the wild. This type of study is called
a simulation
Political pollsters now make sure to conduct a percentage of their telephone interviews by calling mobile phones. This policy best addresses which potential source of bias?
lack of access
Researchers are conducting a survey about what brand of ice cream shoppers prefer. They survey the tenth person who walks into the store and then every fifth person after that. This type of sampling is called
systematic random sampling
Brand Y Cola sponsors a survey of 15,559 residents of Texas to determine which brand of cola they prefer. Forty percent say they prefer Brand X, and 60 percent say they prefer Brand Y. Which of the following is the population sample?
the 15,559 residents
A market research company wants to collect opinions on the comfort and performance of a new type of sneaker by Brand X. Which group of individuals would be the best choice for a random sample?
ask every fourth person who is wearing the brand of sneaker
The president of the math club is conducting a survey to see where the twelfth-grade class wants to go on their field trip. Instead of asking the whole class, she surveys only the twelfth-grade members of the math club. She records their choices and plans
convenience sampling
The box plots below show the ages of college students in different math courses.
The mean and median age are more likely to be the same for the students in Math 1.
The stem-and-leaf plot below shows the number of pages each student in the class read the previous evening.
According to the plot, 75% of students read less than
35 pages
The histogram below shows the age distribution of Elizabeth's grandchildren. Which of the following best explains why one graph appears skewed and one graph appears symmetric?
The interval on the x-axis of the histogram is inconsistent.
The stem-and-leaf plot below shows the number of pages each student in a class read the previous evening.
Which statement is true about the data set?
The value of the first quartile is 13.
A histogram shows data that is skewed to the right. Which most likely describes the relationship between the mean and the median?
The mean is greater than the median. The rightmost values in the data set raise the mean more than the median.
The box-and-whisker plot below shows the age distribution of people at a family reunion.Which of the following best explains why one graph appears skewed and one graph appears symmetrical?
The interval of the stem-and-leaf plot is not consistent.
A poll asks shoppers at the mall how many cups of water they typically drink in a day. The results of the poll are listed below.
3, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 10, 10, 10, 10, 11
What is value of the first quartile?
6
Indira makes a box-and-whisker plot of her data. She finds that the distance from the minimum value to the first quartile is greater than the distance between the third quartile and the maximum value. Which is most likely true?
The mean is less than the median because the data is skewed to the left.
A representative from plan 1 wants to use the graph below to sell health plans for his company. How might the graph be redrawn to emphasize the difference between the cost per doctor visit for each of the three plans?
The scale on the y-axis could be changed to 25-40.
Gemma is creating a histogram based on the table below.
Which scale can she use for the vertical axis such that the difference in the heights of the bars is maximized?
25-40
The graphs below display new car values for cars at the same dealership. The graphs display the same data. Which graph is more likely to show a buyer that it is a good time to buy a car?
graph 1 because the x-axis scale makes it look like cars are selling at a lower price
A scientist calculated the mean and standard deviation of a data set to be u=120 and 0=9 She then found that she was missing one data value from the set. She knows that the missing data value was exactly 3 standard deviations away from the mean. What was
147
The test scores of a geometry class are given below.
90, 75, 72, 88, 85
The teacher wants to find the variance for the class population. What is the value of the numerator of the calculation of the variance?
258
Mrs. Rodrigues wants to compare the spread of the test scores of her two biology classes. Which statistic should she use?
standard deviation
A poll worker analyzing the ages of voters found that u=65 and o=5. What is a possible voter age that would give her zx = 1.14? Round your answer to the nearest whole number.
71
Yuri computes the mean and standard deviation for the sample data set 12, 14, 9, and 21. He finds the mean is 14. His steps for finding the standard deviation are below.
Yuri divided by n instead of n -1.
The mean of a set of credit scores is mc021-1.jpg and mc021-2.jpg. Which credit score is within a z-score of 3.3?
720
A set of data has a mean of 12 and a standard deviation of 3. A data point of the set has a z-score of 1.3. What does a z-score of 1.3 mean?
The data point is 1.3 standard deviations away from 12.
Emi computes the mean and variance for the population data set 87, 46, 90, 78, and 89. She finds the mean is 78. Her steps for finding the variance are shown below.
Emi evaluated (46 - 78)2 as -(32)2.