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Finding the Fourth Proportional to 661.19, 906.64 and 638.01

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Solution

The fourth proportional to 661.19, 906.64 and 638.01 is: 874.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.19 : 906.64 = 638.01 : x
  2. Step 2: Convert to fraction form
    661.19/906.64 = 638.01/x
  3. Step 3: Cross multiply
    661.19x = 906.64 × 638.01
  4. Step 4: Simplify right side
    661.19x = 578,443.79
  5. Step 5: Solve for x
    x = 578,443.79/661.19
  6. Step 6: Final answer
    x = 874.86

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.