Home / 1,287.77-1,931.85-421.88

Finding the Fourth Proportional to 1,287.77, 1,931.85 and 421.88

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Solution

The fourth proportional to 1,287.77, 1,931.85 and 421.88 is: 632.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.77 : 1,931.85 = 421.88 : x
  2. Step 2: Convert to fraction form
    1,287.77/1,931.85 = 421.88/x
  3. Step 3: Cross multiply
    1,287.77x = 1,931.85 × 421.88
  4. Step 4: Simplify right side
    1,287.77x = 814,999.22
  5. Step 5: Solve for x
    x = 814,999.22/1,287.77
  6. Step 6: Final answer
    x = 632.88

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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.