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Finding the Fourth Proportional to 521.65, 719.88 and 288.78

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Solution

The fourth proportional to 521.65, 719.88 and 288.78 is: 398.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.65 : 719.88 = 288.78 : x
  2. Step 2: Convert to fraction form
    521.65/719.88 = 288.78/x
  3. Step 3: Cross multiply
    521.65x = 719.88 × 288.78
  4. Step 4: Simplify right side
    521.65x = 207,886.95
  5. Step 5: Solve for x
    x = 207,886.95/521.65
  6. Step 6: Final answer
    x = 398.52

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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.