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Finding the Fourth Proportional to 1,986.91, 2,977.93 and 686.86

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Solution

The fourth proportional to 1,986.91, 2,977.93 and 686.86 is: 1,029.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,986.91 : 2,977.93 = 686.86 : x
  2. Step 2: Convert to fraction form
    1,986.91/2,977.93 = 686.86/x
  3. Step 3: Cross multiply
    1,986.91x = 2,977.93 × 686.86
  4. Step 4: Simplify right side
    1,986.91x = 2,045,421.00
  5. Step 5: Solve for x
    x = 2,045,421.00/1,986.91
  6. Step 6: Final answer
    x = 1,029.45

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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.