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Finding the Fourth Proportional to 899.36, 1,239.28 and 619.68

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Solution

The fourth proportional to 899.36, 1,239.28 and 619.68 is: 853.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    899.36 : 1,239.28 = 619.68 : x
  2. Step 2: Convert to fraction form
    899.36/1,239.28 = 619.68/x
  3. Step 3: Cross multiply
    899.36x = 1,239.28 × 619.68
  4. Step 4: Simplify right side
    899.36x = 767,957.03
  5. Step 5: Solve for x
    x = 767,957.03/899.36
  6. Step 6: Final answer
    x = 853.89

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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.