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Finding the Fourth Proportional to 280.74, 420.65 and 172.22

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Solution

The fourth proportional to 280.74, 420.65 and 172.22 is: 258.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.74 : 420.65 = 172.22 : x
  2. Step 2: Convert to fraction form
    280.74/420.65 = 172.22/x
  3. Step 3: Cross multiply
    280.74x = 420.65 × 172.22
  4. Step 4: Simplify right side
    280.74x = 72,444.34
  5. Step 5: Solve for x
    x = 72,444.34/280.74
  6. Step 6: Final answer
    x = 258.05

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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.