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Finding the Fourth Proportional to 320.42, 478.28 and 317.72

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Solution

The fourth proportional to 320.42, 478.28 and 317.72 is: 474.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.42 : 478.28 = 317.72 : x
  2. Step 2: Convert to fraction form
    320.42/478.28 = 317.72/x
  3. Step 3: Cross multiply
    320.42x = 478.28 × 317.72
  4. Step 4: Simplify right side
    320.42x = 151,959.12
  5. Step 5: Solve for x
    x = 151,959.12/320.42
  6. Step 6: Final answer
    x = 474.25

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.