Home / 1,287.51-1,931.46-421.75

Finding the Fourth Proportional to 1,287.51, 1,931.46 and 421.75

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Solution

The fourth proportional to 1,287.51, 1,931.46 and 421.75 is: 632.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.51 : 1,931.46 = 421.75 : x
  2. Step 2: Convert to fraction form
    1,287.51/1,931.46 = 421.75/x
  3. Step 3: Cross multiply
    1,287.51x = 1,931.46 × 421.75
  4. Step 4: Simplify right side
    1,287.51x = 814,593.26
  5. Step 5: Solve for x
    x = 814,593.26/1,287.51
  6. Step 6: Final answer
    x = 632.69

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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.