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Finding the Fourth Proportional to 990.06, 1,365.50 and 640.14

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Solution

The fourth proportional to 990.06, 1,365.50 and 640.14 is: 882.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.06 : 1,365.50 = 640.14 : x
  2. Step 2: Convert to fraction form
    990.06/1,365.50 = 640.14/x
  3. Step 3: Cross multiply
    990.06x = 1,365.50 × 640.14
  4. Step 4: Simplify right side
    990.06x = 874,111.17
  5. Step 5: Solve for x
    x = 874,111.17/990.06
  6. Step 6: Final answer
    x = 882.89

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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.