Home / 1,128.40-1,557.12-630.80

Finding the Fourth Proportional to 1,128.40, 1,557.12 and 630.80

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Solution

The fourth proportional to 1,128.40, 1,557.12 and 630.80 is: 870.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,128.40 : 1,557.12 = 630.80 : x
  2. Step 2: Convert to fraction form
    1,128.40/1,557.12 = 630.80/x
  3. Step 3: Cross multiply
    1,128.40x = 1,557.12 × 630.80
  4. Step 4: Simplify right side
    1,128.40x = 982,231.30
  5. Step 5: Solve for x
    x = 982,231.30/1,128.40
  6. Step 6: Final answer
    x = 870.46

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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.