Home / 1,109.40-1,668.15-931.20

Finding the Fourth Proportional to 1,109.40, 1,668.15 and 931.20

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Solution

The fourth proportional to 1,109.40, 1,668.15 and 931.20 is: 1,400.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,109.40 : 1,668.15 = 931.20 : x
  2. Step 2: Convert to fraction form
    1,109.40/1,668.15 = 931.20/x
  3. Step 3: Cross multiply
    1,109.40x = 1,668.15 × 931.20
  4. Step 4: Simplify right side
    1,109.40x = 1,553,381.28
  5. Step 5: Solve for x
    x = 1,553,381.28/1,109.40
  6. Step 6: Final answer
    x = 1,400.20

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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.