Chapter 9.B, Problem 32E

Equations from Two Data Points. Create the required linear function, and use it to answer the following questions.

1. Suppose your pet dog weighed 2.5 pounds at birth and weighed 15 pounds one year later. Based on these two data points, find a linear function that describes how weight varies with age. Use this function to predict your dog's weight at 5 and 10 years of age. Comment on the validity of the model-
2. You can purchase a motorcycle far $6500 or lease it (or a down payment of $200 and $150 per month. Find a function that describes how the cost of the lease depends on time.
How long can you lease the motorcycle before you've paid more than its purchase price?
3. A Campus Republicans fundraiser offers raffle tickets for $10 each. The prize for the rattle is a $350 television set, which must he purchased with proceeds horn the ticket sales. Find a function that gives the profit/loss for the raffle as it varies with the number of tickets sold. How many tickets must be sold for the raffle sales to equal the cost of the prize?
4. The Campus Democrats plan to pay a visitor $100 to speak at a fundraiser. Tickets will be sold for $4 apiece. Find a function that gives the profit/loss for the event as it vanes with the number of tickets sold. How many people must attend the event for the club to break even?
5. A $1200 washing machine in a laundromat is depreciated for tax purposes at a rate of $75 per year. Find a function for the
depreciated value of the washing machine as It vanes with time. When does the deprecated value reach $0?
6. A mining company can extract 2000 tons of gold ore per day with a purity of 3 ounces of gold per ton. The cost of extraction is $1000 per ton. If p is the price of gold in dollars per ounce, find a function that gives the daily profit/loss of the mine as it vanes with the price of gold. What is the minimum price of gold that makes the mine profitable?