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Finding the Fourth Proportional to 815.47, 1,125.34 and 479.30

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Solution

The fourth proportional to 815.47, 1,125.34 and 479.30 is: 661.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.47 : 1,125.34 = 479.30 : x
  2. Step 2: Convert to fraction form
    815.47/1,125.34 = 479.30/x
  3. Step 3: Cross multiply
    815.47x = 1,125.34 × 479.30
  4. Step 4: Simplify right side
    815.47x = 539,368.64
  5. Step 5: Solve for x
    x = 539,368.64/815.47
  6. Step 6: Final answer
    x = 661.42

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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.