Question

1. Camilla won $150 in a drawing contest. She spent 5/8 art supplies. How much money does she have left?

A $56.25
B $68.75
C $93.75
D $131.25

2. Kelly paid a one-time membership fee of $56.80 when joining a gym, and since then she has been paying $22.70 per month. So far she has paid the gym $374.60. For how many months has Kelly been a member of the gym?

3. The 20 students in Ms. Wilson's art class made a project with construction paper. Nine students used red construction paper, 5 students used green construction paper, and the rest of the students used blue construction paper. If Ms. Wilson chooses one project at random, what is the probability that it Will be blue?

4. The battery on Sarah's old cömputer can last for 3 3/4 hours. She bought a new computer that has a battery that can last 20% longer. How long can the battery on Sarah's new computer last?

5.Kendra needs to buy a window shade to cover a window in her living room. She measured the width of the window shade as 68 inches. The actual measurement is 72 inches. What is Kendra's percent error? Round your answer to the nearest tenth.

6. Kyle bought a sofa for d dollars and paid an 8% sales tax. Write two different expressions that represent the total number of dollars, including tax, that Kyle spent, and show or explain why the expressions are equivalent.

7. Michael and Nadia are on their school(s swim team. They each swam 5 laps and recorded their lap times in seconds.
Michael's Lap Times (seconds) 42, 43, 45, 4.7, 48
Nadia's Lap Times (seconds) 36, 37, 46, 50, 51
Who has the greater mean absolute deviation, and by how much? Show or explain how you know.

Answer 1

#1

• 150*(1 - 5/8) = 150(3/8) = 56.25
• Option A

#2

• 56.80 + 22.70x = 374.60
• 22.7x = 374.60 - 56.80
• 22.7x = 317.8
• x = 317.8/22.7
• x = 14 months

#3

• Blue = 20 - (9 + 5) = 6
• p(blue) = 6/20 = 0.3 or 30%

#4

• 3 3/4 + 20% of 3 3/4 =
• 3 3/4*1.2 =
• 15/4 * 12/10 =
• 9/2 = 4.5 hr

#5

Actual value = 72 in, expected value = 68 in

• Error = 72 - 68 = 4 in
• Percent error = error/ expected value * 100% =
• 4/68*100% = 5.9% (rounded)

#6

• d + 8% = d + 0.08d = 1.08d
• d*1.08 = 1.08d

#7

Michael

• Data = 42, 43, 45, 4.7, 48
• Mean = (42+ 43+ 45+ 47+ 48) / 5 = 45
• Absolute deviation = (|42 - 45| + |43 - 45| + |45 - 45| + |47 -45| + |48 - 45|)/5 = 2

Nadia

• Data = 36, 37, 46, 50, 51
• Mean = (36+ 37+ 46+ 50+ 51)/5 = 44
• Absolute deviation = (|36 - 44| + |37 - 44| + |46 - 44|+ |50 -44| + |51 - 44|)/5= 6

Nadia had greater mean absolute deviation: 6 - 2 = 4 (seconds)