Toy stores have discovered that the number of Tickle Me Elmo toys

1

• Toy stores have discovered that the number of
  Tickle Me Elmo toys
• sold in a month decreases as the price increases.
  This means that
• the number N, in hundreds of Tickle Me Elmos
  sold is a function of
• the price, P in dollars of each toy.
  Specifically, at K-Mart, this function
• is N 78 1.3P. At Toys R Us, this function
  is N 93 1.6P.
• Neither store will sell Tickle Me Elmo for less
  than 25.
• 1. How many Tickle Me Elmos will K-Mart sell in
  a month if they charge 40 per toy?
• 2. What price should Toys R Us charge for
  Tickle Me Elmo in order to sell 3,700
• of them? Show an algebraic solution.
• 3. If both stores sold the same number of Tickle
  Me Elmos in March, what price did
• they charge? Show an algebraic solution.
• 4. Verify your answer to question 3 using the
  graphing option on the calculator. Call your
  teacher over to see your groups calculator
  screen.
• Use the Toys R Us formula to obtain a formula
  expressing P as a function of N.

2
K-Mart N 78 1.3P.
Toys R Us N 93 1.6P
Both stores charged 50 per toy
and each sold 1,300 Tickle Me Elmos.
3
Answers to even-numbered HW problems
Section 2.3 Ex 18 a) t b) She
will weigh 68 pounds at age 8.5 years.
c) i. She will be 55.3 inches tall when she
weighs 68 pounds.
ii. h .225w 40 or h w 40
4
The state of Washington is one of worlds largest
producers of grapes. The grapes
grown in the state are used to make both wine and
grape
juice. However, wine is more profitable. One of
the reasons the state has
been so successful in the production of wine is
its relatively dry climate.
If there is too little rain, the grape crop
suffers. If there is too much
rain, grapes are still produced, but they are
unsuitable for making wine and
are used in the manufacture of grape juice. Wine
industry experts have developed a
model for the number of barrels of wine produced
per acre as a function of the average
number of inches of rainfall per year. The
model is
Where R number of inches of rainfall per year
and W number of barrels of wine produced per
acre.
5
Where R number of inches of rainfall per year
and W number of barrels
of wine produced per acre.

• Make a graph of W versus R. Use a horizontal
  scale from 3 to 25.
• Explain what is meant by W(14) and find its
  value.
• 3. If, in a certain year, the wine production
  was 23 barrels per acre, what does
• the model indicate the amount of rainfall
  was that year? Answer to the
• nearest hundredth of an inch.
• 4. What amount of rainfall will produce the
  highest number of barrels of wine per acre?
  Answer to the nearest hundredth of an inch.

6
Where R number of inches of rainfall per year
and W number of barrels
of wine produced per acre.

• Make a graph of W versus R. Use a horizontal
  scale from 3 to 25.
• Explain what is meant by W(14) and find its
  value.
• 3. If, in a certain year, the wine production
  was 23 barrels per acre, what does
• the model indicate the amount of rainfall
  was that year? Answer to the
• nearest hundredth of an inch.
• 4. What amount of rainfall will produce the
  highest number of barrels of wine per acre?
  Answer to the nearest hundredth of an inch.

W(14) represents the number of barrels of wine
produced per acre if there are 14
inches of rainfall. W(14) 57.4
7
Where R number of inches of rainfall per year
and W number of barrels
of wine produced per acre.

• Make a graph of W versus R. Use a horizontal
  scale from 3 to 25.
• Explain what is meant by W(14) and find its
  value.
• 3. If, in a certain year, the wine production
  was 23 barrels per acre, what does
• the model indicate the amount of rainfall
  was that year? Answer to the
• nearest hundredth of an inch.
• 4. What amount of rainfall will produce the
  highest number of barrels of wine per acre?
  Answer to the nearest hundredth of an inch.

W(14) represents the number of barrels of wine
produced per acre if there are 14
inches of rainfall. W(14) 57.4
23 barrels per acre will be produced with 3.63
inches or 22.84 inches of rain.
8
Where R number of inches of rainfall per year
and W number of barrels
of wine produced per acre.

• Make a graph of W versus R. Use a horizontal
  scale from 3 to 25.
• Explain what is meant by W(14) and find its
  value.
• 3. If, in a certain year, the wine production
  was 23 barrels per acre, what does
• the model indicate the amount of rainfall
  was that year? Answer to the
• nearest hundredth of an inch.
• 4. What amount of rainfall will produce the
  highest number of barrels of wine per acre?
  Answer to the nearest hundredth of an inch.

W(14) represents the number of barrels of wine
produced per acre if there are 14
inches of rainfall. W(14) 57.4
23 barrels per acre will be produced with 3.63
inches or 22.84 inches of rain.
12.86 inches of rain will produce the highest
number of barrels (57.86).
9
At birth, the average tyrannosaurus was 3 feet
long. A full grown T-Rex could be as much as 50
feet long. Paleontologists have formulated a
model that identifies the approximate weight of a
tyrannosaurus as a function of its overall length
during the T-Rexs lifetime. That model is given
by the function where W weight in tons, and L
length in feet.

• Make a graph of W versus L.
• What was the approximate weight of a
  tyrannosaurus at birth?

3. To the nearest tenth of a foot, how long
would an 11 ton tyrannosaurus be?
10
Homework Read section 2.4 (through top of page
153) Page 157 S-5 Pages 158 161 5, 9,
19 Read section 2.5 (through top of page
170) Page 172 S-1 Pages 172 177 2,
18,19 AND PRACTICE TEST 1