9-3 Making Predictions from Data

​Making Predictions

from Data

​The following are review.

Math Response

The circle graph shows the results of a survey about

favorite kinds of books. If 600 people were surveyed, how many more people prefer mystery books than historical fiction books?

Type answer here

Correct Answer: 48

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Math Response

The circle graph shows the amount a family spent at a park. If the family spent

$30 on rides, how much did they spend in all?

Type answer here

Correct Answer: 120

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Math Response

The circle graph shows the results of a survey about

favorite kinds of books. If 600 people were surveyed, how many more people prefer comedy books than fantasy books?

Type answer here

Correct Answer: 102

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​Learning Intent:  I am learning to make predictions based on data gathered.

Success Criteria:  I can make accurate predictions based on data gathered using a valid sampling method.

​Making Predictions from Data

Vocabulary

• Statistics deal with collecting, organizing and analyzing data.

• A survey is a method of collecting information.

• The whole group being studied is called the population. Sometimes a population can be really large.

• To save time and money, part of the group, called a sample is surveyed.

• To make a prediction, you analyze the data given from the sample and project it onto the population.

Our Method

Let's use proportional reasoning to solve these types of problems.

1. Set up a proportion.
2. Cross multiply and divide to find the information we need.

​I do:

​I do:

​We do:

Math Response

The table shows the results of a school survey about favorite pizza flavors. If there are 1,064​ students in the school, predict how many would select pepperoni as their favorite flavor.​

Type answer here

Correct Answer: 304

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Multiple Choice

A survey of visitors at a national park was conducted to determine the preferred activity of each visitor to the park. Each visitor chose one activity. The survey results are shown in the table.

Based on this information, which prediction about the preferred activity for the next 200 visitors to the park is the most reasonable?

• The number of visitors who prefer water sports will be 5 more than the number of visitors who prefer biking trails.

• The number of visitors who prefer hiking trails will be 8 more than the number of visitors who prefer water sports.

• The number of visitors who prefer camping will be 15 times the number of visitors who prefer hiking trails.

• The number of visitors who prefer camping will be 2 times the number of visitors who prefer water sports.

Predictions using percents.

​Learning Intent:  I am learning to make predictions based on data gathered.

Success Criteria:  I can make accurate predictions based on data gathered using a valid sampling method.

Math Response

Warmup

90% of 45

Type answer here

Correct Answer: 40.5

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Math Response

Warmup

35% of 7

Type answer here

Correct Answer: 2.45

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​I do:

​I do:

Solution:
34% do not volunteer, therefore 66% do volunteer. (100-34 = 66%)
Find 66% of 2,000. Use part = % x whole.
# of volunteers = .66(2000)

About 1,320 students volunteer regularly.

​We do:

​We do:

Solution:
If 37% do not buy popcorn, 63% do. (100%-37% = 63%)
Find 63% of 3,200. Use part = % x whole.
0.63(3200) = 2016

The theatre can expect 2016 customers to buy popcorn.

Math Response

You do:

The superintendent of a school district wants to predict next year's middle school lunch count. She conducted a survey in which randomly selected middle school students were asked, "Do you typically buy a school lunch

each week?" Approximately 63% of respondents said they do not typically buy a school lunch. If the district has 5,000 middle school students next year, about how many students plan to buy lunch each week?

Type answer here

Correct Answer: 1850

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Math Response

You do:

The guidance department conducted a random survey of the student body and found that 84% of the students do not plan to volunteer at the school festival. Predict how many volunteer positions they should plan for a population of 950 students.

Type answer here

Correct Answer: 1850

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Math Response

An employer is planning to buy lunch for all his employees. The graph shows the results of a random survey of his employees’ lunch preferences. How many Italian sandwiches can the employer expect to buy if he has 84 employees?

Type answer here

Correct Answer: 21

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Math Response

A football coach is planning on purchasing training videos for each player who misses his summer camp. He randomly asks 15 players, and 4 of them say they will miss the camp. How many players out of 75 can the coach expect to miss the summer camp?

Type answer here

Correct Answer: 20

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Math Response

A volunteer organization randomly surveys 40 volunteers about their shirt color preference. The graph shows the results of the survey. Predict how many volunteers will want a black shirt if the organization has 350 volunteers.

Type answer here

Correct Answer: 98

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Math Response

A mayor wants to know how many people in her town drive certain types of vehicles. She records 50 types of vehicles as they pass the busiest intersection in town.

The table shows the results. How many electric vehicles can the mayor expect out of 4,000 vehicles in the town?

Type answer here

Correct Answer: 20

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Math Response

A town is organizing a summer festival. The planners want to have enough gift bags for every person who attends. Out of 100 people randomly surveyed, 47 said they would attend the festival. How many gift bags should the planners prepare if there are 2,800 people in the town?

Type answer here

Correct Answer: 1316

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Math Response

The principal is planning a year-end volunteer activity for the eighth grade. She randomly surveys 20 students. The table shows the results. If there are 140 eighth graders, how many students can the principal expect to choose to volunteer at a food pantry?

Type answer here

Correct Answer: 42

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Math Response

Out of all the readers who visit a blog, 11% click on an advertisement. Predict how many readers will click on an advertisement if 500 people visit the blog in one day.

Type answer here

Correct Answer: 55

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Math Response

An extended family has a potluck dinner for a holiday to which every household brings a food item. Of all the food, 20% are desserts. Predict how many desserts will be at the meal if 25 households bring food items.

Type answer here

Correct Answer: 5

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Math Response

An environmental scientist collects data on fish in a large lake. She finds that 26% of all the fish have an infection. Predict how many fish have an infection if 900 fish are in the lake.

Type answer here

Correct Answer: 234

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