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Finding the Fourth Proportional to 690.40, 952.80 and 379.92

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Solution

The fourth proportional to 690.40, 952.80 and 379.92 is: 524.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.40 : 952.80 = 379.92 : x
  2. Step 2: Convert to fraction form
    690.40/952.80 = 379.92/x
  3. Step 3: Cross multiply
    690.40x = 952.80 × 379.92
  4. Step 4: Simplify right side
    690.40x = 361,987.78
  5. Step 5: Solve for x
    x = 361,987.78/690.40
  6. Step 6: Final answer
    x = 524.32

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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.