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Finding the Fourth Proportional to 862.67, 1,290.06 and 643.45

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Solution

The fourth proportional to 862.67, 1,290.06 and 643.45 is: 962.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.67 : 1,290.06 = 643.45 : x
  2. Step 2: Convert to fraction form
    862.67/1,290.06 = 643.45/x
  3. Step 3: Cross multiply
    862.67x = 1,290.06 × 643.45
  4. Step 4: Simplify right side
    862.67x = 830,082.66
  5. Step 5: Solve for x
    x = 830,082.66/862.67
  6. Step 6: Final answer
    x = 962.23

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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.