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Finding the Fourth Proportional to 871.26, 1,307.70 and 690.63

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Solution

The fourth proportional to 871.26, 1,307.70 and 690.63 is: 1,036.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.26 : 1,307.70 = 690.63 : x
  2. Step 2: Convert to fraction form
    871.26/1,307.70 = 690.63/x
  3. Step 3: Cross multiply
    871.26x = 1,307.70 × 690.63
  4. Step 4: Simplify right side
    871.26x = 903,136.85
  5. Step 5: Solve for x
    x = 903,136.85/871.26
  6. Step 6: Final answer
    x = 1,036.59

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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.