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Finding the Fourth Proportional to 870.79, 1,306.26 and 315.38

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Solution

The fourth proportional to 870.79, 1,306.26 and 315.38 is: 473.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.79 : 1,306.26 = 315.38 : x
  2. Step 2: Convert to fraction form
    870.79/1,306.26 = 315.38/x
  3. Step 3: Cross multiply
    870.79x = 1,306.26 × 315.38
  4. Step 4: Simplify right side
    870.79x = 411,968.28
  5. Step 5: Solve for x
    x = 411,968.28/870.79
  6. Step 6: Final answer
    x = 473.10

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.