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Finding the Fourth Proportional to 838.86, 1,158.74 and 644.78

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Solution

The fourth proportional to 838.86, 1,158.74 and 644.78 is: 890.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.86 : 1,158.74 = 644.78 : x
  2. Step 2: Convert to fraction form
    838.86/1,158.74 = 644.78/x
  3. Step 3: Cross multiply
    838.86x = 1,158.74 × 644.78
  4. Step 4: Simplify right side
    838.86x = 747,132.38
  5. Step 5: Solve for x
    x = 747,132.38/838.86
  6. Step 6: Final answer
    x = 890.65

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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.