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Finding the Fourth Proportional to 666.68, 920.51 and 405.05

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Solution

The fourth proportional to 666.68, 920.51 and 405.05 is: 559.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.68 : 920.51 = 405.05 : x
  2. Step 2: Convert to fraction form
    666.68/920.51 = 405.05/x
  3. Step 3: Cross multiply
    666.68x = 920.51 × 405.05
  4. Step 4: Simplify right side
    666.68x = 372,852.58
  5. Step 5: Solve for x
    x = 372,852.58/666.68
  6. Step 6: Final answer
    x = 559.27

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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.