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Finding the Fourth Proportional to 663.65, 915.59 and 398.10

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Solution

The fourth proportional to 663.65, 915.59 and 398.10 is: 549.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.65 : 915.59 = 398.10 : x
  2. Step 2: Convert to fraction form
    663.65/915.59 = 398.10/x
  3. Step 3: Cross multiply
    663.65x = 915.59 × 398.10
  4. Step 4: Simplify right side
    663.65x = 364,497.37
  5. Step 5: Solve for x
    x = 364,497.37/663.65
  6. Step 6: Final answer
    x = 549.24

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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.