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Finding the Fourth Proportional to 665.64, 918.82 and 645.16

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Solution

The fourth proportional to 665.64, 918.82 and 645.16 is: 890.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.64 : 918.82 = 645.16 : x
  2. Step 2: Convert to fraction form
    665.64/918.82 = 645.16/x
  3. Step 3: Cross multiply
    665.64x = 918.82 × 645.16
  4. Step 4: Simplify right side
    665.64x = 592,785.91
  5. Step 5: Solve for x
    x = 592,785.91/665.64
  6. Step 6: Final answer
    x = 890.55

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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.