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Finding the Fourth Proportional to 666.75, 920.22 and 387.10

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Solution

The fourth proportional to 666.75, 920.22 and 387.10 is: 534.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.75 : 920.22 = 387.10 : x
  2. Step 2: Convert to fraction form
    666.75/920.22 = 387.10/x
  3. Step 3: Cross multiply
    666.75x = 920.22 × 387.10
  4. Step 4: Simplify right side
    666.75x = 356,217.16
  5. Step 5: Solve for x
    x = 356,217.16/666.75
  6. Step 6: Final answer
    x = 534.26

Related Problems

Find fourth proportional to 333.38, 460.11 and 193.55
Half scale
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Double scale
Find fourth proportional to 667.75, 921.60 and 388.10
Similar ratio
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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.