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Finding the Fourth Proportional to 669.85, 924.31 and 390.14

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Solution

The fourth proportional to 669.85, 924.31 and 390.14 is: 538.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.85 : 924.31 = 390.14 : x
  2. Step 2: Convert to fraction form
    669.85/924.31 = 390.14/x
  3. Step 3: Cross multiply
    669.85x = 924.31 × 390.14
  4. Step 4: Simplify right side
    669.85x = 360,605.68
  5. Step 5: Solve for x
    x = 360,605.68/669.85
  6. Step 6: Final answer
    x = 538.34

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1.5x scale

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.