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Finding the Fourth Proportional to 643.80, 888.27 and 381.72

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Solution

The fourth proportional to 643.80, 888.27 and 381.72 is: 526.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.80 : 888.27 = 381.72 : x
  2. Step 2: Convert to fraction form
    643.80/888.27 = 381.72/x
  3. Step 3: Cross multiply
    643.80x = 888.27 × 381.72
  4. Step 4: Simplify right side
    643.80x = 339,070.42
  5. Step 5: Solve for x
    x = 339,070.42/643.80
  6. Step 6: Final answer
    x = 526.67

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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.