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Finding the Fourth Proportional to 815.12, 1,123.76 and 789.62

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Solution

The fourth proportional to 815.12, 1,123.76 and 789.62 is: 1,088.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.12 : 1,123.76 = 789.62 : x
  2. Step 2: Convert to fraction form
    815.12/1,123.76 = 789.62/x
  3. Step 3: Cross multiply
    815.12x = 1,123.76 × 789.62
  4. Step 4: Simplify right side
    815.12x = 887,343.37
  5. Step 5: Solve for x
    x = 887,343.37/815.12
  6. Step 6: Final answer
    x = 1,088.60

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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.