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Finding the Fourth Proportional to 1,239.80, 1,858.50 and 459.58

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Solution

The fourth proportional to 1,239.80, 1,858.50 and 459.58 is: 688.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,239.80 : 1,858.50 = 459.58 : x
  2. Step 2: Convert to fraction form
    1,239.80/1,858.50 = 459.58/x
  3. Step 3: Cross multiply
    1,239.80x = 1,858.50 × 459.58
  4. Step 4: Simplify right side
    1,239.80x = 854,129.43
  5. Step 5: Solve for x
    x = 854,129.43/1,239.80
  6. Step 6: Final answer
    x = 688.93

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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.