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Finding the Fourth Proportional to 815.86, 1,126.20 and 521.38

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Solution

The fourth proportional to 815.86, 1,126.20 and 521.38 is: 719.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.86 : 1,126.20 = 521.38 : x
  2. Step 2: Convert to fraction form
    815.86/1,126.20 = 521.38/x
  3. Step 3: Cross multiply
    815.86x = 1,126.20 × 521.38
  4. Step 4: Simplify right side
    815.86x = 587,178.16
  5. Step 5: Solve for x
    x = 587,178.16/815.86
  6. Step 6: Final answer
    x = 719.70

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Double scale
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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.