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Finding the Fourth Proportional to 864.80, 1,290.51 and 772.51

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Solution

The fourth proportional to 864.80, 1,290.51 and 772.51 is: 1,152.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.80 : 1,290.51 = 772.51 : x
  2. Step 2: Convert to fraction form
    864.80/1,290.51 = 772.51/x
  3. Step 3: Cross multiply
    864.80x = 1,290.51 × 772.51
  4. Step 4: Simplify right side
    864.80x = 996,928.65
  5. Step 5: Solve for x
    x = 996,928.65/864.80
  6. Step 6: Final answer
    x = 1,152.78

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.