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Finding the Fourth Proportional to 1,986.72, 2,980.12 and 688.23

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Solution

The fourth proportional to 1,986.72, 2,980.12 and 688.23 is: 1,032.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,986.72 : 2,980.12 = 688.23 : x
  2. Step 2: Convert to fraction form
    1,986.72/2,980.12 = 688.23/x
  3. Step 3: Cross multiply
    1,986.72x = 2,980.12 × 688.23
  4. Step 4: Simplify right side
    1,986.72x = 2,051,007.99
  5. Step 5: Solve for x
    x = 2,051,007.99/1,986.72
  6. Step 6: Final answer
    x = 1,032.36

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.