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Finding the Fourth Proportional to 653.42, 978.82 and 421.50

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Solution

The fourth proportional to 653.42, 978.82 and 421.50 is: 631.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.42 : 978.82 = 421.50 : x
  2. Step 2: Convert to fraction form
    653.42/978.82 = 421.50/x
  3. Step 3: Cross multiply
    653.42x = 978.82 × 421.50
  4. Step 4: Simplify right side
    653.42x = 412,571.58
  5. Step 5: Solve for x
    x = 412,571.58/653.42
  6. Step 6: Final answer
    x = 631.41

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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.