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Finding the Fourth Proportional to 253.68, 379.80 and 172.40

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Solution

The fourth proportional to 253.68, 379.80 and 172.40 is: 258.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.68 : 379.80 = 172.40 : x
  2. Step 2: Convert to fraction form
    253.68/379.80 = 172.40/x
  3. Step 3: Cross multiply
    253.68x = 379.80 × 172.40
  4. Step 4: Simplify right side
    253.68x = 65,477.52
  5. Step 5: Solve for x
    x = 65,477.52/253.68
  6. Step 6: Final answer
    x = 258.11

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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.