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Finding the Fourth Proportional to 781.40, 1,078.36 and 432.16

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Solution

The fourth proportional to 781.40, 1,078.36 and 432.16 is: 596.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.40 : 1,078.36 = 432.16 : x
  2. Step 2: Convert to fraction form
    781.40/1,078.36 = 432.16/x
  3. Step 3: Cross multiply
    781.40x = 1,078.36 × 432.16
  4. Step 4: Simplify right side
    781.40x = 466,024.06
  5. Step 5: Solve for x
    x = 466,024.06/781.40
  6. Step 6: Final answer
    x = 596.40

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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.