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Finding the Fourth Proportional to 521.78, 720.32 and 325.40

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Solution

The fourth proportional to 521.78, 720.32 and 325.40 is: 449.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.78 : 720.32 = 325.40 : x
  2. Step 2: Convert to fraction form
    521.78/720.32 = 325.40/x
  3. Step 3: Cross multiply
    521.78x = 720.32 × 325.40
  4. Step 4: Simplify right side
    521.78x = 234,386.90
  5. Step 5: Solve for x
    x = 234,386.90/521.78
  6. Step 6: Final answer
    x = 449.21

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1.5x scale

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.