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Example 3-2c Objective Predict actions of a larger group by using a sample

Example 3-2c Vocabulary Survey A question or set of questions designed to collect data about a specific group of people

Example 3-2c Vocabulary Population The entire group of items or individuals from which the samples under consideration are taken

Example 3-2c Vocabulary Random sample A sample in which the members are selected purely on the basis of chance

Example 3-2c Vocabulary Data Pieces of information that are often numerical

Lesson 3 Contents Example 1Predict Using Percent Proportion Example 2Predict Using Percent Equation We will practice both the percent proportion and the percent equation You may use either method during homework practice or on the test but must use one or the other

Example 3-1a PETS The table shows the results of a survey in which people were asked whether their house pets watch television. Predict how many of the 540 people surveyed said their pets watch TV. Does your pet watch television? ResponsePercent yes 38% no 60% don’t know 2% Write percent proportion 1/2 This is total people surveyed

Example 3-1a PETS The table shows the results of a survey in which people were asked whether their house pets watch television. Predict how many of the 540 people surveyed said their pets watch TV. Does your pet watch television? ResponsePercent yes 38% no 60% don’t know 2% 38 % said their pets watched TV 1/2

Example 3-1a PETS The table shows the results of a survey in which people were asked whether their house pets watch television. Predict how many of the 540 people surveyed said their pets watch TV. Does your pet watch television? ResponsePercent yes 38% no 60% don’t know 2% 1/2 Define variable Refers to the part of the total how many said their pets watch TV

Example 3-1b Find cross products Multiply Ask “what is being done to the variable?” The variable is being multiplied by 100 Do the inverse on both sides 1/2

Example 3-1b Using the fraction bar, divide both sides by 100 Answer: 205 of the people surveyed said pets watch TV 100a = 20,  a Since the dimensional analysis is people must round to whole number 1/2 Bring down 100a = 20,520 Combine “like” terms = Use the Identity Property to multiply 1  a a = How many people surveyed said their pets watch TV.

Example 3-1c AFTER-SCHOOL ACTIVITIES In a survey of middle school students, 32% responded that playing video games was their favorite after-school activity. Predict how many of the 260 students surveyed said that playing video games was their favorite after-school activity. Answer: 83 students said playing video games was their favorite activity 1/2

Example 3-2a SUMMER JOBS According to one survey, 25% of high school students reported they would not get a summer job. Predict how many of the 948 students at Mohawk High School will not get a summer job. Words Variable Equation What number is 25% of 948? Let n represent how many will not get a job 2/2 how many of the 948 students will not get a summer job Part = percent of total n = 0.25  948

Example 3-2b The variable is already by itself Answer: 237 students will not get a summer job. Multiply. 2/2 Add dimensional analysis How many students will not get a summer job?

Example 3-2c WEATHER According to one survey, 31% of adults consider spring to be their favorite season of the year. Predict how many of the 525 employees of a large corporation would respond that spring is their favorite season of the year. Answer: 163 employees considered spring their favorite season * 2/2

End of Lesson 3 Assignment Lesson 8:3Using Statistics to Predict All