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Finding the Fourth Proportional to 521.40, 719.48 and 288.51

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Solution

The fourth proportional to 521.40, 719.48 and 288.51 is: 398.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.40 : 719.48 = 288.51 : x
  2. Step 2: Convert to fraction form
    521.40/719.48 = 288.51/x
  3. Step 3: Cross multiply
    521.40x = 719.48 × 288.51
  4. Step 4: Simplify right side
    521.40x = 207,577.17
  5. Step 5: Solve for x
    x = 207,577.17/521.40
  6. Step 6: Final answer
    x = 398.12

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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.