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Finding the Fourth Proportional to 860.39, 1,187.32 and 487.32

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Solution

The fourth proportional to 860.39, 1,187.32 and 487.32 is: 672.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.39 : 1,187.32 = 487.32 : x
  2. Step 2: Convert to fraction form
    860.39/1,187.32 = 487.32/x
  3. Step 3: Cross multiply
    860.39x = 1,187.32 × 487.32
  4. Step 4: Simplify right side
    860.39x = 578,604.78
  5. Step 5: Solve for x
    x = 578,604.78/860.39
  6. Step 6: Final answer
    x = 672.49

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Double scale
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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.