Home / 1,257.20-1,885.80-391.60

Finding the Fourth Proportional to 1,257.20, 1,885.80 and 391.60

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Solution

The fourth proportional to 1,257.20, 1,885.80 and 391.60 is: 587.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,257.20 : 1,885.80 = 391.60 : x
  2. Step 2: Convert to fraction form
    1,257.20/1,885.80 = 391.60/x
  3. Step 3: Cross multiply
    1,257.20x = 1,885.80 × 391.60
  4. Step 4: Simplify right side
    1,257.20x = 738,479.28
  5. Step 5: Solve for x
    x = 738,479.28/1,257.20
  6. Step 6: Final answer
    x = 587.40

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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.