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Finding the Fourth Proportional to 666.80, 919.41 and 561.72

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Solution

The fourth proportional to 666.80, 919.41 and 561.72 is: 774.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.80 : 919.41 = 561.72 : x
  2. Step 2: Convert to fraction form
    666.80/919.41 = 561.72/x
  3. Step 3: Cross multiply
    666.80x = 919.41 × 561.72
  4. Step 4: Simplify right side
    666.80x = 516,448.18
  5. Step 5: Solve for x
    x = 516,448.18/666.80
  6. Step 6: Final answer
    x = 774.52

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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.