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Finding the Fourth Proportional to 642.12, 886.20 and 380.16

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Solution

The fourth proportional to 642.12, 886.20 and 380.16 is: 524.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.12 : 886.20 = 380.16 : x
  2. Step 2: Convert to fraction form
    642.12/886.20 = 380.16/x
  3. Step 3: Cross multiply
    642.12x = 886.20 × 380.16
  4. Step 4: Simplify right side
    642.12x = 336,897.79
  5. Step 5: Solve for x
    x = 336,897.79/642.12
  6. Step 6: Final answer
    x = 524.66

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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.