Measures of Center
What are the three Measures of Center?
What is...
Mean, Median, and Mode
What does a measure of variability describe?
What is...
It describes how spread out the data is.
Is this an example of a population or a sample?
The CEO of a company meets with each employee to ask if they are satisfied with their job.
What is...
Population
*See table
Forty 6th graders and forty 7th graders are surveyed to see where they would like to go on their field trip this year.
True or False: 25% of 7th graders want to go to the museum for their field trip.
What is...
False, 25% of 7th graders want to go to the sports complex for the field trip.
*See box plot
The 4th and 6th grade students at Tree Hill Elementary completed a survey on how many extracurricular activities they participate in. The data is shown in the box plot.
In the box plot, which quartiles of the 4th and 6th graders are equal to each other?
What is...
The first quartile of the 6th graders & the 2nd quartile (median) of the 4th graders.
Find the mean of the follow set of data points:
108, 52, 87, 73, 95, 43, 102
What is...
80
What percent of the data does the Interquartile Range represent?
What is...
50%
Is this an example of a sample or a population?
A fast-food restaurant asks every 6th car in the drive thru line about which menu item is their favorite.
What is...
Sample
*See table
Forty 6th graders and forty 7th graders are surveyed to see where they would like to go on their field trip this year.
If there are 200 members of the 8th grade class, then how many students can be expected to prefer the zoo.
What is...
70 8th graders
*See box plot
The 4th and 6th grade students at Tree Hill Elementary completed a survey on how many extracurricular activities they participate in. The data is shown in the box plot.
Which grade has a greater variability?
What is...
The 6th Graders
What is the median of the following data set:
95, 52, 43, 75, 108, 87
What is...
81
M.A.D. helps to describe how spread out the data is. What does it mean when the M.A.D. is close to 0?
What is...
The data values are close to the mean.
A new restaurant in town is surveying residents to determine how much they typically pay for a meal out. Why is the following NOT a random sample?
They randomly select 50 residents of a local nursing home.
What is...
Although the sample is random, people in a nursing home may not eat out a lot. Therefore, they would not be a good representation of the population.
An internet company randomly selected 40 of its customers and asked them how many hours per week they use the internet. Of those surveyed, 12 use the internet more than 10 hours per week. Based on the data, if the company has 600 subscribers, how many use the internet more than 10 hours a week?
What is...
180 subscribers
*See Dot Plot
The number of TVs per household for Mrs. Jamison's class and Mr. Zimmerman's class is shown below.
What shape does the data from Mrs. Jamison's Class have?
What is...
Skewed to the right
*See Dot Plot
The number of TVs per household for Mrs. Jamison's class and Mr. Zimmerman's class is shown below.
What is the difference between the medians of these two dot plots?
What is...
1
Bella is looking to buy a car. At the dealership, Bella is told that the price of the cars have a range of $943. She knows that the cheapest car is $4,780. What is the maximum amount that a car will cost at this dealership?
What is...
$5,723
The elementary school cafeteria is considering changing the menu from pizza to sub sandwiches. They conduct a survey of the elementary school. Why is the following NOT a random sample?
Twenty randomly selected fifth graders are surveyed.
What is...
There are multiple grades in the elementary school, not just fifth graders.
A restaurant polls every tenth guest to determine if they are satisfied with the cleanliness of the establishment. Sixty guests are surveyed, and 18 are satisfied. What conclusion can be drawn for the 400 daily guests?
A. 30% of the guests are unsatisfied with the cleanliness of the restaurant.
B. Of the 400 guests, 112 would be unsatisfied with the cleanliness of the restaurant.
C. Of the 400 guests, 120 would be satisfied with the cleanliness of the restaurant.
What is...
C. Of the 400 guests, 120 would be satisfied with the cleanliness of the store.
*See Box Plot
The 4th and 6th grade students at Tree Hill Elementary completed a survey on how many extracurricular activities they participate in. The data is shown in the box plot.
What is the interquartile range of each box plot?
What is...
Mrs. Jamison's Class - 1.9
Mr. Zimmerman's Class - 1
What is the definition of mode?
What is...
The number that appears the most times in a data set.
Find the M.A.D. of the following data points:
3, 6, 9, 4, 5, 3
What is...
Mean: 5
Total Deviation: 10
M.A.D.: 1.67
Determine a possible random sample for the following situation:
An ice cream truck would like to decide which flavors to carry on its route this summer.
What is...
Ex: Go up to every 5th door on its route.
See Table:
Forty 6th graders and forty 7th graders are surveyed to see where they would like to go on their field trip this year.
True or False: More than 25% of the 8th grade students would like to go to the zoo.
What is...
True, 35% of the 8th grade students would like to go to the zoo.
*See Dot Plot
The number of TVs per household for Mrs. Jamison's class and Mr. Zimmerman's class is shown below.
The mean absolute deviation of Mrs. Jamison's class is 0.24. What does this mean?
What is...
The data is very close to the center.
The data is close to 0, so it is not very spread out.
The data does not have a lot of variability.