Home / 1,287.24-1,931.18-421.53

Finding the Fourth Proportional to 1,287.24, 1,931.18 and 421.53

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Solution

The fourth proportional to 1,287.24, 1,931.18 and 421.53 is: 632.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.24 : 1,931.18 = 421.53 : x
  2. Step 2: Convert to fraction form
    1,287.24/1,931.18 = 421.53/x
  3. Step 3: Cross multiply
    1,287.24x = 1,931.18 × 421.53
  4. Step 4: Simplify right side
    1,287.24x = 814,048.20
  5. Step 5: Solve for x
    x = 814,048.20/1,287.24
  6. Step 6: Final answer
    x = 632.40

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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.