1. Section 3.4 – Exponential and Logarithmic Equations Section 3.5 – Exponential and Logarithmic Models

2. Solve the following equations!

5. You have deposited $500 in an account that pays 6.75% interest CC. How long will it take to double your money?

6. From 1990 to 1997 the Consumer Price Index (CPI) value y for a fixed amount of sugar for the year t can be modeled by the equation where t = 10 represents 1970. During which year did the price of sugar reach 4.5 times its 1970 price of 30.5 on the CPI?

7. In 1997, the SAT math scores for college- bound seniors followed a normal distribution where x is the SAT score for math. Graph this function on the calculator and find the average SAT score.

8. On a college campus of 5000 students, one students returns from vacation with a contagious flu virus. The spread of the virus is modeled by where y is the total number of infected students after t days. The college will cancel classes when 40% or more of the students are infected. a) How many students are infected after 5 days? b) After how many days will the college cancel class?

9. On the Richter Scale, the magnitude R of an earthquake of intensity I is modeled by the equation Find the intensities per unit area for the following earthquakes and then find out how much stronger one earthquake was than the other. 1)Tokyo, Japan in 1923: R=8.3 2)Kobe, Japan in 1995: R = 7.2

10. In computer class, the average number of words per minutes typed after t weeks of lessons was found to be Find the time necessary to type: a) 50 words per minute b) 75 words per minute c) 200 words per minute