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Finding the Fourth Proportional to 839.51, 1,158.93 and 643.89

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Solution

The fourth proportional to 839.51, 1,158.93 and 643.89 is: 888.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.51 : 1,158.93 = 643.89 : x
  2. Step 2: Convert to fraction form
    839.51/1,158.93 = 643.89/x
  3. Step 3: Cross multiply
    839.51x = 1,158.93 × 643.89
  4. Step 4: Simplify right side
    839.51x = 746,223.44
  5. Step 5: Solve for x
    x = 746,223.44/839.51
  6. Step 6: Final answer
    x = 888.89

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.