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Finding the Fourth Proportional to 915.38, 1,262.72 and 620.80

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Solution

The fourth proportional to 915.38, 1,262.72 and 620.80 is: 856.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    915.38 : 1,262.72 = 620.80 : x
  2. Step 2: Convert to fraction form
    915.38/1,262.72 = 620.80/x
  3. Step 3: Cross multiply
    915.38x = 1,262.72 × 620.80
  4. Step 4: Simplify right side
    915.38x = 783,896.58
  5. Step 5: Solve for x
    x = 783,896.58/915.38
  6. Step 6: Final answer
    x = 856.36

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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.