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Finding the Fourth Proportional to 305.09, 420.98 and 172.30

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Solution

The fourth proportional to 305.09, 420.98 and 172.30 is: 237.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.09 : 420.98 = 172.30 : x
  2. Step 2: Convert to fraction form
    305.09/420.98 = 172.30/x
  3. Step 3: Cross multiply
    305.09x = 420.98 × 172.30
  4. Step 4: Simplify right side
    305.09x = 72,534.23
  5. Step 5: Solve for x
    x = 72,534.23/305.09
  6. Step 6: Final answer
    x = 237.75

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.