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Finding the Fourth Proportional to 642.51, 963.86 and 209.56

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Solution

The fourth proportional to 642.51, 963.86 and 209.56 is: 314.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.51 : 963.86 = 209.56 : x
  2. Step 2: Convert to fraction form
    642.51/963.86 = 209.56/x
  3. Step 3: Cross multiply
    642.51x = 963.86 × 209.56
  4. Step 4: Simplify right side
    642.51x = 201,986.50
  5. Step 5: Solve for x
    x = 201,986.50/642.51
  6. Step 6: Final answer
    x = 314.37

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.