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Finding the Fourth Proportional to 668.40, 922.49 and 388.80

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Solution

The fourth proportional to 668.40, 922.49 and 388.80 is: 536.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.40 : 922.49 = 388.80 : x
  2. Step 2: Convert to fraction form
    668.40/922.49 = 388.80/x
  3. Step 3: Cross multiply
    668.40x = 922.49 × 388.80
  4. Step 4: Simplify right side
    668.40x = 358,663.63
  5. Step 5: Solve for x
    x = 358,663.63/668.40
  6. Step 6: Final answer
    x = 536.60

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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.