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Finding the Fourth Proportional to 910, 1,256.30 and 641.23

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Solution

The fourth proportional to 910, 1,256.30 and 641.23 is: 885.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    910 : 1,256.30 = 641.23 : x
  2. Step 2: Convert to fraction form
    910/1,256.30 = 641.23/x
  3. Step 3: Cross multiply
    910x = 1,256.30 × 641.23
  4. Step 4: Simplify right side
    910x = 805,577.25
  5. Step 5: Solve for x
    x = 805,577.25/910
  6. Step 6: Final answer
    x = 885.25

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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.