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Finding the Fourth Proportional to 378.40, 567.56 and 287.65

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Solution

The fourth proportional to 378.40, 567.56 and 287.65 is: 431.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.40 : 567.56 = 287.65 : x
  2. Step 2: Convert to fraction form
    378.40/567.56 = 287.65/x
  3. Step 3: Cross multiply
    378.40x = 567.56 × 287.65
  4. Step 4: Simplify right side
    378.40x = 163,258.44
  5. Step 5: Solve for x
    x = 163,258.44/378.40
  6. Step 6: Final answer
    x = 431.45

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.