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Finding the Fourth Proportional to 860.32, 1,187.20 and 487.20

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Solution

The fourth proportional to 860.32, 1,187.20 and 487.20 is: 672.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.32 : 1,187.20 = 487.20 : x
  2. Step 2: Convert to fraction form
    860.32/1,187.20 = 487.20/x
  3. Step 3: Cross multiply
    860.32x = 1,187.20 × 487.20
  4. Step 4: Simplify right side
    860.32x = 578,403.84
  5. Step 5: Solve for x
    x = 578,403.84/860.32
  6. Step 6: Final answer
    x = 672.31

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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.