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Finding the Fourth Proportional to 870.65, 1,200.78 and 538.76

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Solution

The fourth proportional to 870.65, 1,200.78 and 538.76 is: 743.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.65 : 1,200.78 = 538.76 : x
  2. Step 2: Convert to fraction form
    870.65/1,200.78 = 538.76/x
  3. Step 3: Cross multiply
    870.65x = 1,200.78 × 538.76
  4. Step 4: Simplify right side
    870.65x = 646,932.23
  5. Step 5: Solve for x
    x = 646,932.23/870.65
  6. Step 6: Final answer
    x = 743.05

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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.