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Finding the Fourth Proportional to 642.64, 886.86 and 380.86

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Solution

The fourth proportional to 642.64, 886.86 and 380.86 is: 525.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.64 : 886.86 = 380.86 : x
  2. Step 2: Convert to fraction form
    642.64/886.86 = 380.86/x
  3. Step 3: Cross multiply
    642.64x = 886.86 × 380.86
  4. Step 4: Simplify right side
    642.64x = 337,769.50
  5. Step 5: Solve for x
    x = 337,769.50/642.64
  6. Step 6: Final answer
    x = 525.60

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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.