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Finding the Fourth Proportional to 990.79, 1,487.30 and 625.79

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Solution

The fourth proportional to 990.79, 1,487.30 and 625.79 is: 939.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.79 : 1,487.30 = 625.79 : x
  2. Step 2: Convert to fraction form
    990.79/1,487.30 = 625.79/x
  3. Step 3: Cross multiply
    990.79x = 1,487.30 × 625.79
  4. Step 4: Simplify right side
    990.79x = 930,738.06
  5. Step 5: Solve for x
    x = 930,738.06/990.79
  6. Step 6: Final answer
    x = 939.39

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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.