Home / 1,121.18-1,681.79-390.77

Finding the Fourth Proportional to 1,121.18, 1,681.79 and 390.77

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Solution

The fourth proportional to 1,121.18, 1,681.79 and 390.77 is: 586.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.18 : 1,681.79 = 390.77 : x
  2. Step 2: Convert to fraction form
    1,121.18/1,681.79 = 390.77/x
  3. Step 3: Cross multiply
    1,121.18x = 1,681.79 × 390.77
  4. Step 4: Simplify right side
    1,121.18x = 657,193.08
  5. Step 5: Solve for x
    x = 657,193.08/1,121.18
  6. Step 6: Final answer
    x = 586.16

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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.