Name ______Date ______
Math 7ACMaking Predications
A survey is a method of collecting information. The group being studied is the population. To save time and money, part of the group, called a sample, is surveyed.A good sample is:
• selected at random, or without preference,
• representative of the population, and
• large enough to provide accurate data.
Every sixth student who walked into the school was asked how he or
she got to school.
1) What is the probability that a student at the school rode a bike to school?
P(ride bike) =
2) There are 360 students at the school. Predict how manybike to school.
Write a proportion and solve:
EXERCISES:
SCHOOLUse the following information and the table shown. Every tenth student entering the school was asked which one of the four subjects was his or her favorite.
1)Find the probability that any student attending school prefers science.
2)There are 400 students at the school. Predict how manystudents would prefer science.
QUIZ SHOW: On a quiz show, a contestant correctly answered 9 of the last 12 questions.
3)Based on these results, find the probability of the contestant correctly answering the next question.
4)Suppose the contestant continues on the show and tries to correctly answer 24 questions. About how many questions would you predict the contestant to correctly answer?
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CHORES: Use the table to predict the number of students out of 528 that would say each of the following
was their least favorite chore.
5) clean my room6) wash dishes
7) walk the dog8) take out the garbage
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GARDENING:A survey showed that 74% of a nursery’s mail-ordercustomers spent more than $100 on plants each spring. Predict how many of 125,000 mail-order customers will spend less than $100 on plants next spring.
SAVINGMONEY:A survey of high school students with jobs asked whetherthe students saved some of the money they earned. 82% of the students said they saved some money. Out of 340 students, predict how many would save some of their earnings.
Name ______Date ______
Math 7ACPredicitons H.W.
Use the table and the followinginformation. A survey of students’ favorite sports was taken from a
random sample of students ina school. The results are shown in the table.
1)What is the size of the sample?
2)What is the probability that a student will prefersoccer?
3)What is the probability that a student will prefer volleyball?
4)There are 550 students in the school. Predict how many students at the school prefertrack and field.
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The circle graph shows the results of a survey of teens and where they would prefer to spend a family vacation.
5) Predict how many of 4,000 teens would prefer to go to an amusement park. 1,
6)In 2000, about 29% of the foreign visitors to the U.S. were from Canada. If a particular hotel had 150,000 foreign guests in one year, how many would you predict were from Canada?
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7)TRAVELCOMPANYCUSTOMERS:A survey showed that 55% of a travelcompany’s customers were planning an overseas vacation the following year. Predict how many of the travel company’s 12,400 travelers will vacation overseas the following year.
BOOKS:The results of a survey asking teens their favorite typeof book to read is shown.
8)Out of 250 teens, predict how many would choose mystery as theirfavorite type of book to read
9)Out of 250 teens, predict how many would choose adventure as their favorite type ofbook to read.
10)Out of 250 teens, predict how many would choose science fiction as their favorite typeof book to read.
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MOVIES: Use the table of results of Jeremy’s survey of favorite kinds of movies.
11)How many people did Jeremy use for his sample?
12)If Jeremy were to ask any person to name his or her favorite type of movie, what is the probability that it would be comedy?
13)If Jeremy were to survey 250 people how many would you predict would name comedy?
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14)HAIRCUT: Survey results show that 68% of people tip their hairdresser when they get a haircut. Predict how many people out of 150 tip their hairdresser.
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15)GOLF: A survey showed that 28% of adults play golf in their free time. Out of 1550 adults, predict how many would say they play golf.