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Finding the Fourth Proportional to 561.63, 775.13 and 387.21

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Solution

The fourth proportional to 561.63, 775.13 and 387.21 is: 534.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.63 : 775.13 = 387.21 : x
  2. Step 2: Convert to fraction form
    561.63/775.13 = 387.21/x
  3. Step 3: Cross multiply
    561.63x = 775.13 × 387.21
  4. Step 4: Simplify right side
    561.63x = 300,136.15
  5. Step 5: Solve for x
    x = 300,136.15/561.63
  6. Step 6: Final answer
    x = 534.40

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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.