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Finding the Fourth Proportional to 860.51, 1,290.33 and 421.81

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Solution

The fourth proportional to 860.51, 1,290.33 and 421.81 is: 632.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.51 : 1,290.33 = 421.81 : x
  2. Step 2: Convert to fraction form
    860.51/1,290.33 = 421.81/x
  3. Step 3: Cross multiply
    860.51x = 1,290.33 × 421.81
  4. Step 4: Simplify right side
    860.51x = 544,270.87
  5. Step 5: Solve for x
    x = 544,270.87/860.51
  6. Step 6: Final answer
    x = 632.50

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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.