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Finding the Fourth Proportional to 663.40, 915.78 and 427.60

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Solution

The fourth proportional to 663.40, 915.78 and 427.60 is: 590.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.40 : 915.78 = 427.60 : x
  2. Step 2: Convert to fraction form
    663.40/915.78 = 427.60/x
  3. Step 3: Cross multiply
    663.40x = 915.78 × 427.60
  4. Step 4: Simplify right side
    663.40x = 391,587.53
  5. Step 5: Solve for x
    x = 391,587.53/663.40
  6. Step 6: Final answer
    x = 590.27

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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.