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Finding the Fourth Proportional to 390.69, 538.72 and 266.13

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Solution

The fourth proportional to 390.69, 538.72 and 266.13 is: 366.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.69 : 538.72 = 266.13 : x
  2. Step 2: Convert to fraction form
    390.69/538.72 = 266.13/x
  3. Step 3: Cross multiply
    390.69x = 538.72 × 266.13
  4. Step 4: Simplify right side
    390.69x = 143,368.89
  5. Step 5: Solve for x
    x = 143,368.89/390.69
  6. Step 6: Final answer
    x = 366.96

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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.