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Finding the Fourth Proportional to 870.12, 1,200.80 and 497.16

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Solution

The fourth proportional to 870.12, 1,200.80 and 497.16 is: 686.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.12 : 1,200.80 = 497.16 : x
  2. Step 2: Convert to fraction form
    870.12/1,200.80 = 497.16/x
  3. Step 3: Cross multiply
    870.12x = 1,200.80 × 497.16
  4. Step 4: Simplify right side
    870.12x = 596,989.73
  5. Step 5: Solve for x
    x = 596,989.73/870.12
  6. Step 6: Final answer
    x = 686.10

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.