Algebra 2 Normal Curve Analysis Extra Practice The mean and standard deviation are given for several classes below. For each one, set up and label a normal curve for each data set including the mean and 3 standard deviation marks on each side. Then for each curve give the test score range that would account for 68%, 95% and 99.7% of the scores. 1. Class 1 : mean = 65 and standard deviation = 12 68% = __________ 95% = __________ 99.7% = ___________ 2. Class 2: mean = 74 and standard deviation = 8. 3. Class 3 mean = 76 and standard deviation = 7 99.7% = __________ Using Class #3 above, what percentage of the data would be: Between 83 and 97? 5. Greater than 69? Less than 83? Greater than 62? Less than 90? Between 76 and 90?

Ticket in the door 12-11 Normal Curve Percentages The mean and standard deviation are given for a class below. Set up and label a normal curve for the data set including the mean and 3 standard deviation marks on each side. Then give the test score range that would account for 68%, 95% and 99.7% of the scores. 1. Class 1 : mean = 74 and standard deviation = 9 68% = __________ 95% = __________ 99.7% = ___________ Use your curve above to tell what percentage is: Greater than 65? Between 56 and 101? Between 47 and 74? Less than 92? Greater than 83? Less than 74?

EXTRA EXAMPLES Finding Standard Normal Curve Percentages The mean and standard deviation are given for a class below. Set up and label a normal curve for the data set including the mean and 3 standard deviation marks on each side. Then give the test score range that would account for 68%, 95% and 99.7% of the scores. 1. Class 3 : mean = 81 and standard deviation = 4 68% = __________ 95% = __________ 99.7% = ___________ Use the curve above to tell what percentage is: Less than 73? Greater than 69? Between 77 and 89? 5. Between 81 and 93?

Ticket out the door 12-11 Sampling, Biased vs. Unbiased For each problem below. Name the type of sampling used. An employer requests 20 volunteers to answer the questions on a survey. A teacher asks every 4th person in their class to answer survey questions. A high school football coach asks all the seniors on the team to respond to a group of questions. A student asks the people sitting with them at lunch to fill out a survey. A teacher uses a computer to randomly select 30 of their students to respond to survey questions. For each sentence below, indicate whether the statement is biased or unbiased. What is your favorite extra curricular activity? 7. Wouldn’t it be better if teachers assigned less homework?

Types of Sampling/Biased vs. Unbiased Statements For each problem below. Name the type of sampling used. A company asks every 4th employee that works for them. A company sends out surveys through email and requests their customers to respond. A company asks only the employees with 10 or more years of experience to take a survey. A company randomly selects 100 of their employees to answer questions on a survey. A company asks only the employees that are present on the day the surveys are printed to take the survey. A principal asks 100 randomly chosen freshman, sophomores, juniors, and seniors to take a survey. A teacher uses a random number generator on their computer to select 50 of their students to take a survey. A subdivision asks the opinions of all the people that live on a specific street in the subdivision. A coach asks every 4th player that shows up to practice to answer the questions on a short A student asks 20 people in their class the questions on a survey. The cafeteria in a high school asks for 100 volunteers to fill out a survey about the quality of the food served. 12. A teacher selects 10 boys and 10 girls in their class to fill out a short survey.

Types of Sampling/Biased vs. Unbiased Statements For each sentence below, indicate whether the statement is biased or unbiased. 13. What do you think about the condition of the state’s roadways? Don’t you think that the state should adopt a lottery for education? . Do you believe that the tardy policy should be changed since the existing one is too lenient? What is your favorite type of car? Do you believe that Almost There Tests should be eliminated completely? Do you believe the school calendar should be changed so that students get more time off? What do you think of the current attendance policy?

Measures of Spread Practice For the following sets of data numbers: List them from least to greatest. Find the mean, standard deviation, and variance 87,87, 20, 80, 60, 80, 60, 80, 87, 82, 87 a. b. Mean = Standard Deviation= Variance = Range = 2. 80,80,74,93,87,34,80,93,100,93,80,87 3. 72,80,76,80,74,115,96,84,92,48,88,80,80 4. 69,86,34,99,60,95,96,74,84,93 5. 100,12,97,64,70,64,100,91,94,56,71 6. 100,97,45,89,38,86,87,93,44,90,73,55,78

Measures of Spread Examples For the following sets of data numbers: List them from least to greatest. Find the mean, standard deviation, and variance 1. 91,98,89,40,77,90,100,99,86,69,91 a. b. Mean = Standard Deviation= Variance = Range = 2 40, 74, 91, 98,72,85, 71,71,75, 46, 92,91, 55, 125 3. 57,77,70,97,86,94,47,66,38,72,80,53,81 4 80,33, 78,70,28,75,97,75,63,84,55,52

Ticket Out the Door 12-11 For the following sets of data numbers: List them from least to greatest. Find the mean, standard deviation, and variance 88,100,96,82,44,80,74,90,96,32, 86, 96 a. b. Mean = Standard Deviation= Variance = Range = 2. 88,46,58,92,46,84,100,35,85,54,96