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Finding the Fourth Proportional to 290.78, 400.79 and 187.10

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Solution

The fourth proportional to 290.78, 400.79 and 187.10 is: 257.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.78 : 400.79 = 187.10 : x
  2. Step 2: Convert to fraction form
    290.78/400.79 = 187.10/x
  3. Step 3: Cross multiply
    290.78x = 400.79 × 187.10
  4. Step 4: Simplify right side
    290.78x = 74,987.81
  5. Step 5: Solve for x
    x = 74,987.81/290.78
  6. Step 6: Final answer
    x = 257.89

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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.