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Finding the Fourth Proportional to 871.79, 1,307.40 and 286.65

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Solution

The fourth proportional to 871.79, 1,307.40 and 286.65 is: 429.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.79 : 1,307.40 = 286.65 : x
  2. Step 2: Convert to fraction form
    871.79/1,307.40 = 286.65/x
  3. Step 3: Cross multiply
    871.79x = 1,307.40 × 286.65
  4. Step 4: Simplify right side
    871.79x = 374,773.13
  5. Step 5: Solve for x
    x = 374,773.13/871.79
  6. Step 6: Final answer
    x = 429.89

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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.