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Finding the Fourth Proportional to 670.16, 924.91 and 390.40

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Solution

The fourth proportional to 670.16, 924.91 and 390.40 is: 538.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.16 : 924.91 = 390.40 : x
  2. Step 2: Convert to fraction form
    670.16/924.91 = 390.40/x
  3. Step 3: Cross multiply
    670.16x = 924.91 × 390.40
  4. Step 4: Simplify right side
    670.16x = 361,084.86
  5. Step 5: Solve for x
    x = 361,084.86/670.16
  6. Step 6: Final answer
    x = 538.80

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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.