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Finding the Fourth Proportional to 979.01, 1,349.69 and 663.80

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Solution

The fourth proportional to 979.01, 1,349.69 and 663.80 is: 915.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.01 : 1,349.69 = 663.80 : x
  2. Step 2: Convert to fraction form
    979.01/1,349.69 = 663.80/x
  3. Step 3: Cross multiply
    979.01x = 1,349.69 × 663.80
  4. Step 4: Simplify right side
    979.01x = 895,916.02
  5. Step 5: Solve for x
    x = 895,916.02/979.01
  6. Step 6: Final answer
    x = 915.12

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.