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Finding the Fourth Proportional to 772.80, 1,065.72 and 521.29

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Solution

The fourth proportional to 772.80, 1,065.72 and 521.29 is: 718.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    772.80 : 1,065.72 = 521.29 : x
  2. Step 2: Convert to fraction form
    772.80/1,065.72 = 521.29/x
  3. Step 3: Cross multiply
    772.80x = 1,065.72 × 521.29
  4. Step 4: Simplify right side
    772.80x = 555,549.18
  5. Step 5: Solve for x
    x = 555,549.18/772.80
  6. Step 6: Final answer
    x = 718.88

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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.