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Finding the Fourth Proportional to 398.40, 549.28 and 310.08

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Solution

The fourth proportional to 398.40, 549.28 and 310.08 is: 427.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.40 : 549.28 = 310.08 : x
  2. Step 2: Convert to fraction form
    398.40/549.28 = 310.08/x
  3. Step 3: Cross multiply
    398.40x = 549.28 × 310.08
  4. Step 4: Simplify right side
    398.40x = 170,320.74
  5. Step 5: Solve for x
    x = 170,320.74/398.40
  6. Step 6: Final answer
    x = 427.51

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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.