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Finding the Fourth Proportional to 778.65, 1,173.32 and 644.69

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Solution

The fourth proportional to 778.65, 1,173.32 and 644.69 is: 971.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.65 : 1,173.32 = 644.69 : x
  2. Step 2: Convert to fraction form
    778.65/1,173.32 = 644.69/x
  3. Step 3: Cross multiply
    778.65x = 1,173.32 × 644.69
  4. Step 4: Simplify right side
    778.65x = 756,418.58
  5. Step 5: Solve for x
    x = 756,418.58/778.65
  6. Step 6: Final answer
    x = 971.45

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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.