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Finding the Fourth Proportional to 858.47, 1,287.69 and 242.15

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Solution

The fourth proportional to 858.47, 1,287.69 and 242.15 is: 363.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.47 : 1,287.69 = 242.15 : x
  2. Step 2: Convert to fraction form
    858.47/1,287.69 = 242.15/x
  3. Step 3: Cross multiply
    858.47x = 1,287.69 × 242.15
  4. Step 4: Simplify right side
    858.47x = 311,817.35
  5. Step 5: Solve for x
    x = 311,817.35/858.47
  6. Step 6: Final answer
    x = 363.23

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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.