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Finding the Fourth Proportional to 870.84, 1,306.29 and 285.84

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Solution

The fourth proportional to 870.84, 1,306.29 and 285.84 is: 428.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.84 : 1,306.29 = 285.84 : x
  2. Step 2: Convert to fraction form
    870.84/1,306.29 = 285.84/x
  3. Step 3: Cross multiply
    870.84x = 1,306.29 × 285.84
  4. Step 4: Simplify right side
    870.84x = 373,389.93
  5. Step 5: Solve for x
    x = 373,389.93/870.84
  6. Step 6: Final answer
    x = 428.77

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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.