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Finding the Fourth Proportional to 781.36, 1,078.70 and 571.32

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Solution

The fourth proportional to 781.36, 1,078.70 and 571.32 is: 788.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.36 : 1,078.70 = 571.32 : x
  2. Step 2: Convert to fraction form
    781.36/1,078.70 = 571.32/x
  3. Step 3: Cross multiply
    781.36x = 1,078.70 × 571.32
  4. Step 4: Simplify right side
    781.36x = 616,282.88
  5. Step 5: Solve for x
    x = 616,282.88/781.36
  6. Step 6: Final answer
    x = 788.73

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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.