Home / 1,038.09-1,557.20-421.80

Finding the Fourth Proportional to 1,038.09, 1,557.20 and 421.80

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Solution

The fourth proportional to 1,038.09, 1,557.20 and 421.80 is: 632.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,038.09 : 1,557.20 = 421.80 : x
  2. Step 2: Convert to fraction form
    1,038.09/1,557.20 = 421.80/x
  3. Step 3: Cross multiply
    1,038.09x = 1,557.20 × 421.80
  4. Step 4: Simplify right side
    1,038.09x = 656,824.85
  5. Step 5: Solve for x
    x = 656,824.85/1,038.09
  6. Step 6: Final answer
    x = 632.72

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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.