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Finding the Fourth Proportional to 670.21, 924.77 and 390.42

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Solution

The fourth proportional to 670.21, 924.77 and 390.42 is: 538.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.21 : 924.77 = 390.42 : x
  2. Step 2: Convert to fraction form
    670.21/924.77 = 390.42/x
  3. Step 3: Cross multiply
    670.21x = 924.77 × 390.42
  4. Step 4: Simplify right side
    670.21x = 361,049.68
  5. Step 5: Solve for x
    x = 361,049.68/670.21
  6. Step 6: Final answer
    x = 538.71

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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.