Warm Up- Get a tracking sheet and handout on your way in. Sit in your usual seat and begin working on the warm up. Solve for x Solve for x What is your height? What is your shoe size?

Announcements  Test is Thursday, September 4 th  3 rd block  we have been assigned to C lunch instead of B lunch.  Tutoring is today after school from 2:15 to 3:15. You may come to do your homework if you need a calculator.

Binder Organization  I am passing out a sheet that should go in front of your binders.  Throughout the semester, I will have surprise binder checks (USUALLY on test days )  These should be easy 100s to boost your grade.  In order to earn a 1oo you must:  Have your binder in class  Have it organized the way it is outlined on the sheet I am passing out.

Tracking Sheets  I will return your tracking sheets from last week with quizzes towards the end of class.  Monday was a freebie day.  Each stamp was worth 5 points.  I gave you participation and class work for every day last week because you all got all of your work done.  This week: same thing goes for class work. In order to earn a participation stamp, you must raise your hand to ask a question or answer a question at some point during class.

Calculators  If you do not have your own calculator, I will assign you one to use in class each day.  You must use only that calculator.  All calculators must be returned to the holder before anyone leaves class.

Example 1a A company has created a new widget for sale in the marketplace. When the company priced the widget at $5.00, it made $11,000 in revenues. However, when it priced the product at $10.00, is made $21, Find a linear function that expresses the revenues from the product as a function of price.

Example 1b A company has created a new widget for sale in the marketplace. When the company priced the widget at $5.00, it made $11,000 in revenues. However, when it priced the product at $10.00, is made $21,000. 1c. If the company priced the widget at $12.00, how much would it make in revenues?

Example 1b A company has created a new widget for sale in the marketplace. When the company priced the widget at $5.00, it made $11,000 in revenues. However, when it priced the product at $10.00, is made $21,000. 1d. Would this make sense in the real world? Why or why not?

Definition  Depreciation: the declining value of a product over time  After a certain number of years, the product is worthless.

Example 2a Ms. Army’s business buys a new computer. The computer costs $5,000. It will depreciate to nothing after 10 years. 1. Write a linear function that describes the computer’s value for any given time, t.

Example 2a Ms. Army’s business buys a new computer. The computer costs $5,000. It will depreciate to nothing after 10 years. 2. How much will the computer be worth after 3 years?

Example 2a Ms. Army’s business buys a new computer. The computer costs $5,000. It will depreciate to nothing after 10 years. 3. Say the computer actually depreciated to nothing after 4 years. How much would it be worth in 2 years?

Linear Regression  Regression is a measure of the relationship between one variable (x) and another (y)

Regression  Correlation is NOT causation.  The Line of Best Fit is the line that fits the average of the points. The stronger the correlation the more accurate the line is at describing the relationship.  “r” is the correlation coefficient. -1>0>1  - r values mean negative correlation  + r values mean positive correlation  The closer |r| is to 1 the stronger the correlation.

Line of Best Fit

Practice 1. The number of toppings on a pizza and the cost of the pizza. 2. Your phone battery over the course of the day. 3. Your muscle mass as you start exercising more frequently. 4. The number of siblings you have and your performance in math class.*

Practice  Will “r” be positive or negative?  Will it be close to 1 or 0?

On your calculator  Go to Catalog (Hit 2 nd  0)  Scroll Down until your arrow is beside “diagnostic on” and then hit enter twice.  Now, given a table of values, our calculator will give us both the line of best fit and the correlation coefficient.

Example What type of correlation does this table show? Write a linear regression for the data. How long does a student have to study to earn a 100? If you study 8 hours. What will you earn? How does this answer help us differentiate between correlation and slope?

Example  Enter the data into your calculator by using the STAT button  Look at the scatter plot of the data. Describe the shape of the scatter plot.  Use the LinReg function to create a line of best fit for the data  Superimpose the line over the data. Do you think this model is a good fit for the data?  What is the meaning of the slope of the line?  Use your line of best fit to predict the shoe size of a person who is 90 inches tall.  How tall should someone who has a shoe size of 10.5 be?

Exit Ticket Question A taxicab driver charges $5.00 to enter the vehicle. From that point on, he charges $1.50 per mile. How far would you have driven if you paid $14.00? A* 3 B* 4 C* 5 D* 6

Homework  Finish the problems you did not finish in class.

Quiz Return  Our unit test is this THURSDAY, September 6 th.  If you earn a higher score on your test than you did on this quiz, I will replace this quiz score with your test score.  (Example) If you earned a 70 on this quiz, and an 85 on your test, you will have an 85 in my grade book for both your test and your quiz.  Let’s go over questions that you missed so that you will have the correct answers to study for Thursday.

#1 1st Parentheses and division in 2nd 2nd Parentheses addition Exponent Multiplication Subtraction Addition

#2 Parentheses and top of First fraction Simplify Exponent Simplify Fraction Exponent Subtract

#3 Find the Mistakes is 2 not -6 Must distribute square to everything in parentheses, not just -6 Have to do Add/Sub in order from left to right is not 11

#4 Subtract ax on both sides. Divide both sides by -b Simplify

#5

#6

#7 Cube both Sides Add x on both sides

#8

#9 The multiplicative inverse is what you multiply a number by to make it equal 1.

#10 (3,4) and (-2,14)