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Finding the Fourth Proportional to 869.20, 1,303.80 and 321.45

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Solution

The fourth proportional to 869.20, 1,303.80 and 321.45 is: 482.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.20 : 1,303.80 = 321.45 : x
  2. Step 2: Convert to fraction form
    869.20/1,303.80 = 321.45/x
  3. Step 3: Cross multiply
    869.20x = 1,303.80 × 321.45
  4. Step 4: Simplify right side
    869.20x = 419,106.51
  5. Step 5: Solve for x
    x = 419,106.51/869.20
  6. Step 6: Final answer
    x = 482.18

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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.