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Finding the Fourth Proportional to 778.71, 1,173.40 and 644.76

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Solution

The fourth proportional to 778.71, 1,173.40 and 644.76 is: 971.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.71 : 1,173.40 = 644.76 : x
  2. Step 2: Convert to fraction form
    778.71/1,173.40 = 644.76/x
  3. Step 3: Cross multiply
    778.71x = 1,173.40 × 644.76
  4. Step 4: Simplify right side
    778.71x = 756,561.38
  5. Step 5: Solve for x
    x = 756,561.38/778.71
  6. Step 6: Final answer
    x = 971.56

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.