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Finding the Fourth Proportional to 666.17, 919.28 and 386.39

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Solution

The fourth proportional to 666.17, 919.28 and 386.39 is: 533.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.17 : 919.28 = 386.39 : x
  2. Step 2: Convert to fraction form
    666.17/919.28 = 386.39/x
  3. Step 3: Cross multiply
    666.17x = 919.28 × 386.39
  4. Step 4: Simplify right side
    666.17x = 355,196.97
  5. Step 5: Solve for x
    x = 355,196.97/666.17
  6. Step 6: Final answer
    x = 533.19

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1.5x scale

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.