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Finding the Fourth Proportional to 977.81, 1,351.35 and 780.98

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Solution

The fourth proportional to 977.81, 1,351.35 and 780.98 is: 1,079.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    977.81 : 1,351.35 = 780.98 : x
  2. Step 2: Convert to fraction form
    977.81/1,351.35 = 780.98/x
  3. Step 3: Cross multiply
    977.81x = 1,351.35 × 780.98
  4. Step 4: Simplify right side
    977.81x = 1,055,370.57
  5. Step 5: Solve for x
    x = 1,055,370.57/977.81
  6. Step 6: Final answer
    x = 1,079.33

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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.