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Finding the Fourth Proportional to 210.69, 290.78 and 123.36

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Solution

The fourth proportional to 210.69, 290.78 and 123.36 is: 170.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.69 : 290.78 = 123.36 : x
  2. Step 2: Convert to fraction form
    210.69/290.78 = 123.36/x
  3. Step 3: Cross multiply
    210.69x = 290.78 × 123.36
  4. Step 4: Simplify right side
    210.69x = 35,870.93
  5. Step 5: Solve for x
    x = 35,870.93/210.69
  6. Step 6: Final answer
    x = 170.25

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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.