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Finding the Fourth Proportional to 661.64, 912.65 and 521.72

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Solution

The fourth proportional to 661.64, 912.65 and 521.72 is: 719.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.64 : 912.65 = 521.72 : x
  2. Step 2: Convert to fraction form
    661.64/912.65 = 521.72/x
  3. Step 3: Cross multiply
    661.64x = 912.65 × 521.72
  4. Step 4: Simplify right side
    661.64x = 476,140.59
  5. Step 5: Solve for x
    x = 476,140.59/661.64
  6. Step 6: Final answer
    x = 719.63

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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.