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Finding the Fourth Proportional to 398.19, 549.45 and 315.51

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Solution

The fourth proportional to 398.19, 549.45 and 315.51 is: 435.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.19 : 549.45 = 315.51 : x
  2. Step 2: Convert to fraction form
    398.19/549.45 = 315.51/x
  3. Step 3: Cross multiply
    398.19x = 549.45 × 315.51
  4. Step 4: Simplify right side
    398.19x = 173,356.97
  5. Step 5: Solve for x
    x = 173,356.97/398.19
  6. Step 6: Final answer
    x = 435.36

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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.