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Finding the Fourth Proportional to 704.80, 970.68 and 640

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Solution

The fourth proportional to 704.80, 970.68 and 640 is: 881.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    704.80 : 970.68 = 640 : x
  2. Step 2: Convert to fraction form
    704.80/970.68 = 640/x
  3. Step 3: Cross multiply
    704.80x = 970.68 × 640
  4. Step 4: Simplify right side
    704.80x = 621,235.20
  5. Step 5: Solve for x
    x = 621,235.20/704.80
  6. Step 6: Final answer
    x = 881.43

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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.