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Finding the Fourth Proportional to 3,123.78, 4,685.67 and 815.28

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Solution

The fourth proportional to 3,123.78, 4,685.67 and 815.28 is: 1,222.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,123.78 : 4,685.67 = 815.28 : x
  2. Step 2: Convert to fraction form
    3,123.78/4,685.67 = 815.28/x
  3. Step 3: Cross multiply
    3,123.78x = 4,685.67 × 815.28
  4. Step 4: Simplify right side
    3,123.78x = 3,820,133.04
  5. Step 5: Solve for x
    x = 3,820,133.04/3,123.78
  6. Step 6: Final answer
    x = 1,222.92

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.