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Finding the Fourth Proportional to 670.57, 925.30 and 390.74

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Solution

The fourth proportional to 670.57, 925.30 and 390.74 is: 539.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.57 : 925.30 = 390.74 : x
  2. Step 2: Convert to fraction form
    670.57/925.30 = 390.74/x
  3. Step 3: Cross multiply
    670.57x = 925.30 × 390.74
  4. Step 4: Simplify right side
    670.57x = 361,547.79
  5. Step 5: Solve for x
    x = 361,547.79/670.57
  6. Step 6: Final answer
    x = 539.17

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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.