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Finding the Fourth Proportional to 645.79, 891.10 and 380.30

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Solution

The fourth proportional to 645.79, 891.10 and 380.30 is: 524.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.79 : 891.10 = 380.30 : x
  2. Step 2: Convert to fraction form
    645.79/891.10 = 380.30/x
  3. Step 3: Cross multiply
    645.79x = 891.10 × 380.30
  4. Step 4: Simplify right side
    645.79x = 338,881.35
  5. Step 5: Solve for x
    x = 338,881.35/645.79
  6. Step 6: Final answer
    x = 524.76

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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.