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Finding the Fourth Proportional to 210.81, 316.21 and 89.07

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Solution

The fourth proportional to 210.81, 316.21 and 89.07 is: 133.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.81 : 316.21 = 89.07 : x
  2. Step 2: Convert to fraction form
    210.81/316.21 = 89.07/x
  3. Step 3: Cross multiply
    210.81x = 316.21 × 89.07
  4. Step 4: Simplify right side
    210.81x = 28,162.80
  5. Step 5: Solve for x
    x = 28,162.80/210.81
  6. Step 6: Final answer
    x = 133.60

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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.