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Finding the Fourth Proportional to 620.78, 856.80 and 358.88

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Solution

The fourth proportional to 620.78, 856.80 and 358.88 is: 495.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.78 : 856.80 = 358.88 : x
  2. Step 2: Convert to fraction form
    620.78/856.80 = 358.88/x
  3. Step 3: Cross multiply
    620.78x = 856.80 × 358.88
  4. Step 4: Simplify right side
    620.78x = 307,488.38
  5. Step 5: Solve for x
    x = 307,488.38/620.78
  6. Step 6: Final answer
    x = 495.33

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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.