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Finding the Fourth Proportional to 870.70, 1,298.63 and 839.71

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Solution

The fourth proportional to 870.70, 1,298.63 and 839.71 is: 1,252.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.70 : 1,298.63 = 839.71 : x
  2. Step 2: Convert to fraction form
    870.70/1,298.63 = 839.71/x
  3. Step 3: Cross multiply
    870.70x = 1,298.63 × 839.71
  4. Step 4: Simplify right side
    870.70x = 1,090,472.60
  5. Step 5: Solve for x
    x = 1,090,472.60/870.70
  6. Step 6: Final answer
    x = 1,252.41

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.