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Finding the Fourth Proportional to 860.06, 1,290.30 and 312.20

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Solution

The fourth proportional to 860.06, 1,290.30 and 312.20 is: 468.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.06 : 1,290.30 = 312.20 : x
  2. Step 2: Convert to fraction form
    860.06/1,290.30 = 312.20/x
  3. Step 3: Cross multiply
    860.06x = 1,290.30 × 312.20
  4. Step 4: Simplify right side
    860.06x = 402,831.66
  5. Step 5: Solve for x
    x = 402,831.66/860.06
  6. Step 6: Final answer
    x = 468.38

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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.