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Finding the Fourth Proportional to 642.79, 881.26 and 631.11

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Solution

The fourth proportional to 642.79, 881.26 and 631.11 is: 865.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.79 : 881.26 = 631.11 : x
  2. Step 2: Convert to fraction form
    642.79/881.26 = 631.11/x
  3. Step 3: Cross multiply
    642.79x = 881.26 × 631.11
  4. Step 4: Simplify right side
    642.79x = 556,172.00
  5. Step 5: Solve for x
    x = 556,172.00/642.79
  6. Step 6: Final answer
    x = 865.25

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.