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Finding the Fourth Proportional to 285.70, 394.42 and 215.68

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Solution

The fourth proportional to 285.70, 394.42 and 215.68 is: 297.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.70 : 394.42 = 215.68 : x
  2. Step 2: Convert to fraction form
    285.70/394.42 = 215.68/x
  3. Step 3: Cross multiply
    285.70x = 394.42 × 215.68
  4. Step 4: Simplify right side
    285.70x = 85,068.51
  5. Step 5: Solve for x
    x = 85,068.51/285.70
  6. Step 6: Final answer
    x = 297.75

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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.