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Finding the Fourth Proportional to 900.50, 1,242.26 and 638.66

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Solution

The fourth proportional to 900.50, 1,242.26 and 638.66 is: 881.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    900.50 : 1,242.26 = 638.66 : x
  2. Step 2: Convert to fraction form
    900.50/1,242.26 = 638.66/x
  3. Step 3: Cross multiply
    900.50x = 1,242.26 × 638.66
  4. Step 4: Simplify right side
    900.50x = 793,381.77
  5. Step 5: Solve for x
    x = 793,381.77/900.50
  6. Step 6: Final answer
    x = 881.05

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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.