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Finding the Fourth Proportional to 718.40, 1,082.20 and 621.20

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Solution

The fourth proportional to 718.40, 1,082.20 and 621.20 is: 935.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.40 : 1,082.20 = 621.20 : x
  2. Step 2: Convert to fraction form
    718.40/1,082.20 = 621.20/x
  3. Step 3: Cross multiply
    718.40x = 1,082.20 × 621.20
  4. Step 4: Simplify right side
    718.40x = 672,262.64
  5. Step 5: Solve for x
    x = 672,262.64/718.40
  6. Step 6: Final answer
    x = 935.78

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.