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Finding the Fourth Proportional to 990.30, 1,365.91 and 803.79

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Solution

The fourth proportional to 990.30, 1,365.91 and 803.79 is: 1,108.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.30 : 1,365.91 = 803.79 : x
  2. Step 2: Convert to fraction form
    990.30/1,365.91 = 803.79/x
  3. Step 3: Cross multiply
    990.30x = 1,365.91 × 803.79
  4. Step 4: Simplify right side
    990.30x = 1,097,904.80
  5. Step 5: Solve for x
    x = 1,097,904.80/990.30
  6. Step 6: Final answer
    x = 1,108.66

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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.