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Finding the Fourth Proportional to 421.80, 632.70 and 148.20

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Solution

The fourth proportional to 421.80, 632.70 and 148.20 is: 222.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.80 : 632.70 = 148.20 : x
  2. Step 2: Convert to fraction form
    421.80/632.70 = 148.20/x
  3. Step 3: Cross multiply
    421.80x = 632.70 × 148.20
  4. Step 4: Simplify right side
    421.80x = 93,766.14
  5. Step 5: Solve for x
    x = 93,766.14/421.80
  6. Step 6: Final answer
    x = 222.30

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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.