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Finding the Fourth Proportional to 1,986.19, 2,979.07 and 815.09

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Solution

The fourth proportional to 1,986.19, 2,979.07 and 815.09 is: 1,222.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,986.19 : 2,979.07 = 815.09 : x
  2. Step 2: Convert to fraction form
    1,986.19/2,979.07 = 815.09/x
  3. Step 3: Cross multiply
    1,986.19x = 2,979.07 × 815.09
  4. Step 4: Simplify right side
    1,986.19x = 2,428,193.23
  5. Step 5: Solve for x
    x = 2,428,193.23/1,986.19
  6. Step 6: Final answer
    x = 1,222.54

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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.