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Finding the Fourth Proportional to 653.19, 978.76 and 328.78

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Solution

The fourth proportional to 653.19, 978.76 and 328.78 is: 492.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.19 : 978.76 = 328.78 : x
  2. Step 2: Convert to fraction form
    653.19/978.76 = 328.78/x
  3. Step 3: Cross multiply
    653.19x = 978.76 × 328.78
  4. Step 4: Simplify right side
    653.19x = 321,796.71
  5. Step 5: Solve for x
    x = 321,796.71/653.19
  6. Step 6: Final answer
    x = 492.65

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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.