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Finding the Fourth Proportional to 728.96, 1,097.80 and 638.75

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Solution

The fourth proportional to 728.96, 1,097.80 and 638.75 is: 961.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.96 : 1,097.80 = 638.75 : x
  2. Step 2: Convert to fraction form
    728.96/1,097.80 = 638.75/x
  3. Step 3: Cross multiply
    728.96x = 1,097.80 × 638.75
  4. Step 4: Simplify right side
    728.96x = 701,211.07
  5. Step 5: Solve for x
    x = 701,211.07/728.96
  6. Step 6: Final answer
    x = 961.93

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.