Goal: Solve problems using proportions and percents

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12-13-05

• Goal Solve problems using proportions and
  percents
• Warm-Up pg. 787 15-25 odd
• Hwk

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Solving Proportions
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Writing Proportions

• 1. You are visiting Mexico and want to exchange
  180 for pesos. The rate of currency exchange is
  9.99 pesos per US dollar. How many pesos will
  you receive?

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Writing Proportions

• 2. You tested a sample of 50 tulip bulbs from a
  shipment of 4500 bulbs for resistance to mold.
  You found that 32 of the bulbs had a natural
  resistance and 18 did not. Use the results to
  estimate the number of bulbs in the shipment that
  will have a natural resistance to mold.

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Solving and Writing Proportions

• Lets write and solve the proportions.

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H.S.A. Practice

• Carli spun a spinner 50 times and recorded her
  results in the table below. The spinner had five
  numbered sections.
• Based on the results in the table, how many times
  should Carli expect the spinner to land on
  section 2 or 3 if she spins the spinner 600
  times?

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ECR

• Chris asked 50 randomly selected eleventh-grade
  students to choose their favorite candidate for
  class president. The survey results are shown in
  the table below.
• There are 500 eleventh-grade students at Chris'
  school. Based on the survey results, how many
  votes will Marie expect to receive? Use
  mathematics to explain how you determined your
  answer. Use words, symbols, or both in your
  explanation.

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ECR cont.

• Using the survey results, Chris claims that
  Bertha will receive 2 more votes than Nick in the
  election. Is his correct? Use mathematics to
  justify your answer. 
• Alicia asked the same question in another survey.
  She asked 50 randomly selected eleventh-grade
  chorus students to choose their favorite
  candidate for class president. Will you expect
  Alicia's survey or Chris' survey to give more
  reliable results? Use mathematics to justify your
  answer.

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More H.S.A. Practice

• A student at WMHS conducted a random survey of
  200 tenth-grade students to determine their
  favorite season. The survey results are shown in
  the table below.
• There are 540 tenth-grade students in the school.
  Based on the survey results, how many of these
  tenth-grade students would be expected to choose
  Fall as their favorite season?

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Percent Equations

• Translate
• to decimal
• OF means to multiply
• IS means