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Finding the Fourth Proportional to 400.80, 553.20 and 302.40

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Solution

The fourth proportional to 400.80, 553.20 and 302.40 is: 417.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    400.80 : 553.20 = 302.40 : x
  2. Step 2: Convert to fraction form
    400.80/553.20 = 302.40/x
  3. Step 3: Cross multiply
    400.80x = 553.20 × 302.40
  4. Step 4: Simplify right side
    400.80x = 167,287.68
  5. Step 5: Solve for x
    x = 167,287.68/400.80
  6. Step 6: Final answer
    x = 417.38

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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.