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Finding the Fourth Proportional to 870.39, 1,200.75 and 520.88

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Solution

The fourth proportional to 870.39, 1,200.75 and 520.88 is: 718.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.39 : 1,200.75 = 520.88 : x
  2. Step 2: Convert to fraction form
    870.39/1,200.75 = 520.88/x
  3. Step 3: Cross multiply
    870.39x = 1,200.75 × 520.88
  4. Step 4: Simplify right side
    870.39x = 625,446.66
  5. Step 5: Solve for x
    x = 625,446.66/870.39
  6. Step 6: Final answer
    x = 718.58

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1.5x scale

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.