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Solution
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3)
At the beginning of each school year, Joey and Mateo's mom
marks off their heights on the kitchen wall. Joey measures the
gaps showing annual growth and plots them by the grade level. He notices he grew more between kindergarten and 1st grade than
Mateo by an inch. Which boy has the higher average annual growth and by how much? Round to the nearest tenth of an
inch.
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- Joey's annual growth:
3+2+3+2+2.6+3.8+3.4 = 19.8/7 = 2.82 in/year
- Mateo's annual growth:
2+2.4+1.8+2.2+2.4+3.4+5 = 19.2/7 = 2.74 in/year
- Joey has the higher annual growth rate by
2.82 - 2.74 = .08 inch = 0.1 in.
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4) Molly had a 16 points-per-game average over the first 7 games of the season. In the last five games Molly has scored 28, 16, 20, 24, 18 points respectively. What was her final-points-per
game average? Round to the nearest point.
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Final average =
(16x7 + 28+16+20+24+18)/21 =
218/12 = 18.167 pts/game = 18 points per game
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5) On St. Patrick's day the Leprechaun Bakery sells Lucky Cakes. These cakes are precut into 1 in x 2 in rectangles and one of the pieces has a Lucky Penny hidden in it. Mom is considering the 4 in x 8 in cake and the 9 in x 12 in larger cake. What is the ratio of the probabilities of getting the
piece with the Lucky Penny in the smaller cake to getting the piece with the Lucky Penny in the larger cake? Express your answer as a reduced fraction.
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- # pieces of the smaller cake = 4x8 = 32/2 = 16 pieces
- # pieces of the larger cake = 9x12 = 108/2 = 54 pieces
- Ratio of probabilities =
1⁄16 ÷ 1⁄54 = 54⁄16 = 27⁄8
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