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Finding the Fourth Proportional to 858.02, 1,287.10 and 310.20

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Solution

The fourth proportional to 858.02, 1,287.10 and 310.20 is: 465.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.02 : 1,287.10 = 310.20 : x
  2. Step 2: Convert to fraction form
    858.02/1,287.10 = 310.20/x
  3. Step 3: Cross multiply
    858.02x = 1,287.10 × 310.20
  4. Step 4: Simplify right side
    858.02x = 399,258.42
  5. Step 5: Solve for x
    x = 399,258.42/858.02
  6. Step 6: Final answer
    x = 465.33

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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.