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Finding the Fourth Proportional to 661.22, 912.48 and 381.45

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Solution

The fourth proportional to 661.22, 912.48 and 381.45 is: 526.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.22 : 912.48 = 381.45 : x
  2. Step 2: Convert to fraction form
    661.22/912.48 = 381.45/x
  3. Step 3: Cross multiply
    661.22x = 912.48 × 381.45
  4. Step 4: Simplify right side
    661.22x = 348,067.07
  5. Step 5: Solve for x
    x = 348,067.07/661.22
  6. Step 6: Final answer
    x = 526.40

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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.