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Finding the Fourth Proportional to 858.09, 1,284.69 and 613.89

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Solution

The fourth proportional to 858.09, 1,284.69 and 613.89 is: 919.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.09 : 1,284.69 = 613.89 : x
  2. Step 2: Convert to fraction form
    858.09/1,284.69 = 613.89/x
  3. Step 3: Cross multiply
    858.09x = 1,284.69 × 613.89
  4. Step 4: Simplify right side
    858.09x = 788,658.34
  5. Step 5: Solve for x
    x = 788,658.34/858.09
  6. Step 6: Final answer
    x = 919.09

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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.