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Finding the Fourth Proportional to 415.65, 623.51 and 172.20

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Solution

The fourth proportional to 415.65, 623.51 and 172.20 is: 258.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.65 : 623.51 = 172.20 : x
  2. Step 2: Convert to fraction form
    415.65/623.51 = 172.20/x
  3. Step 3: Cross multiply
    415.65x = 623.51 × 172.20
  4. Step 4: Simplify right side
    415.65x = 107,368.42
  5. Step 5: Solve for x
    x = 107,368.42/415.65
  6. Step 6: Final answer
    x = 258.31

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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.