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Finding the Fourth Proportional to 990.02, 1,364.72 and 815.06

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Solution

The fourth proportional to 990.02, 1,364.72 and 815.06 is: 1,123.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.02 : 1,364.72 = 815.06 : x
  2. Step 2: Convert to fraction form
    990.02/1,364.72 = 815.06/x
  3. Step 3: Cross multiply
    990.02x = 1,364.72 × 815.06
  4. Step 4: Simplify right side
    990.02x = 1,112,328.68
  5. Step 5: Solve for x
    x = 1,112,328.68/990.02
  6. Step 6: Final answer
    x = 1,123.54

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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.