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Finding the Fourth Proportional to 280.90, 420.93 and 172.51

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Solution

The fourth proportional to 280.90, 420.93 and 172.51 is: 258.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.90 : 420.93 = 172.51 : x
  2. Step 2: Convert to fraction form
    280.90/420.93 = 172.51/x
  3. Step 3: Cross multiply
    280.90x = 420.93 × 172.51
  4. Step 4: Simplify right side
    280.90x = 72,614.63
  5. Step 5: Solve for x
    x = 72,614.63/280.90
  6. Step 6: Final answer
    x = 258.51

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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.