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Finding the Fourth Proportional to 209.80, 312.53 and 191.08

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Solution

The fourth proportional to 209.80, 312.53 and 191.08 is: 284.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.80 : 312.53 = 191.08 : x
  2. Step 2: Convert to fraction form
    209.80/312.53 = 191.08/x
  3. Step 3: Cross multiply
    209.80x = 312.53 × 191.08
  4. Step 4: Simplify right side
    209.80x = 59,718.23
  5. Step 5: Solve for x
    x = 59,718.23/209.80
  6. Step 6: Final answer
    x = 284.64

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.