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Finding the Fourth Proportional to 378.47, 521.74 and 278.74

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Solution

The fourth proportional to 378.47, 521.74 and 278.74 is: 384.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.47 : 521.74 = 278.74 : x
  2. Step 2: Convert to fraction form
    378.47/521.74 = 278.74/x
  3. Step 3: Cross multiply
    378.47x = 521.74 × 278.74
  4. Step 4: Simplify right side
    378.47x = 145,430.81
  5. Step 5: Solve for x
    x = 145,430.81/378.47
  6. Step 6: Final answer
    x = 384.26

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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.