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Finding the Fourth Proportional to 660.16, 911.28 and 398.08

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Solution

The fourth proportional to 660.16, 911.28 and 398.08 is: 549.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.16 : 911.28 = 398.08 : x
  2. Step 2: Convert to fraction form
    660.16/911.28 = 398.08/x
  3. Step 3: Cross multiply
    660.16x = 911.28 × 398.08
  4. Step 4: Simplify right side
    660.16x = 362,762.34
  5. Step 5: Solve for x
    x = 362,762.34/660.16
  6. Step 6: Final answer
    x = 549.51

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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.