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Finding the Fourth Proportional to 631.29, 870.75 and 421.38

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Solution

The fourth proportional to 631.29, 870.75 and 421.38 is: 581.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.29 : 870.75 = 421.38 : x
  2. Step 2: Convert to fraction form
    631.29/870.75 = 421.38/x
  3. Step 3: Cross multiply
    631.29x = 870.75 × 421.38
  4. Step 4: Simplify right side
    631.29x = 366,916.64
  5. Step 5: Solve for x
    x = 366,916.64/631.29
  6. Step 6: Final answer
    x = 581.22

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.