Home / 1,285.38-1,918.76-1,129.68

Finding the Fourth Proportional to 1,285.38, 1,918.76 and 1,129.68

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Solution

The fourth proportional to 1,285.38, 1,918.76 and 1,129.68 is: 1,686.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.38 : 1,918.76 = 1,129.68 : x
  2. Step 2: Convert to fraction form
    1,285.38/1,918.76 = 1,129.68/x
  3. Step 3: Cross multiply
    1,285.38x = 1,918.76 × 1,129.68
  4. Step 4: Simplify right side
    1,285.38x = 2,167,584.80
  5. Step 5: Solve for x
    x = 2,167,584.80/1,285.38
  6. Step 6: Final answer
    x = 1,686.34

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.