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Finding the Fourth Proportional to 666.58, 919.91 and 386.76

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Solution

The fourth proportional to 666.58, 919.91 and 386.76 is: 533.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.58 : 919.91 = 386.76 : x
  2. Step 2: Convert to fraction form
    666.58/919.91 = 386.76/x
  3. Step 3: Cross multiply
    666.58x = 919.91 × 386.76
  4. Step 4: Simplify right side
    666.58x = 355,782.46
  5. Step 5: Solve for x
    x = 355,782.46/666.58
  6. Step 6: Final answer
    x = 533.75

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Double scale
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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.