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Finding the Fourth Proportional to 870.38, 1,200.20 and 711.82

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Solution

The fourth proportional to 870.38, 1,200.20 and 711.82 is: 981.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.38 : 1,200.20 = 711.82 : x
  2. Step 2: Convert to fraction form
    870.38/1,200.20 = 711.82/x
  3. Step 3: Cross multiply
    870.38x = 1,200.20 × 711.82
  4. Step 4: Simplify right side
    870.38x = 854,326.36
  5. Step 5: Solve for x
    x = 854,326.36/870.38
  6. Step 6: Final answer
    x = 981.56

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1.5x scale

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.