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Finding the Fourth Proportional to 390.80, 588.65 and 355.16

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Solution

The fourth proportional to 390.80, 588.65 and 355.16 is: 534.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.80 : 588.65 = 355.16 : x
  2. Step 2: Convert to fraction form
    390.80/588.65 = 355.16/x
  3. Step 3: Cross multiply
    390.80x = 588.65 × 355.16
  4. Step 4: Simplify right side
    390.80x = 209,064.93
  5. Step 5: Solve for x
    x = 209,064.93/390.80
  6. Step 6: Final answer
    x = 534.97

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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.