Warm Ups 1) A student has completed 12 out of 34 homework assignments. At this rate, how many assignments would the student complete out of 85 assignments. 2) To make a model of the Victoria River, Zoe used 2.5 inches of clay for every 7 miles of the actual river’s length. Her model river was 50 inches long. How long is the Victoria River? Answers: 1) 30 2) 140

4 - 4 Percents Day 2 Objective: To solve ratio word problems and problems simple interest. Standard 5.0

Similar Triangles (worksheet) 1. A vertical flagpole casts a shadow 12 ft long at the same time that a nearby vertical post 5 ft high casts a shadow 3 ft long. Find the height of the flagpole.

Similar Triangles (worksheet) 2. A vertical rod 8 ft high casts a shadow 6 ft long. At the same time, a nearby tree casts a shadow 15 feet long. Find the height of the tree.

Try #3 with partner Try #4 on your own 3.4. Finish this worksheet for homework!!

Interest Think about these questions.. What is it? Where/When is it earned? Why? Now discuss your answers with a partner.

I = prt I = Interest earned ($) p = principle (amount put in) ($) r = interest rate (as a decimal) (%) t = time (in years) (yrs)

Example 1 Find p if I = $45, r = 6%, and t = ½ year 45 = p(0.06)(.5) 45 =.03p p = $1500

TOO 1. Find p if I = $196, r = 10%, t = 7 years. 2. Find r if I = $120, p = $600, t = 5 years. Answers: 1. p = $ r = 4%

Example 2 Find I if p = $1500, r = 7%, and t = 18 months * change months to years (÷ 12) I = 1500(.07)(18/12) I = 105(1.5) I = $157.50

TOO 1. Find I if p = $500, r = 5%, t = 6 months. 2. Find t if I = $200, p = $1500, r = 1%. Answers: 1. I = $ t = 13.3 years = 13 years 4 months

Homework Similar Triangles worksheet Pg. 219 # all