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Finding the Fourth Proportional to 891.40, 1,228.23 and 641.92

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Solution

The fourth proportional to 891.40, 1,228.23 and 641.92 is: 884.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.40 : 1,228.23 = 641.92 : x
  2. Step 2: Convert to fraction form
    891.40/1,228.23 = 641.92/x
  3. Step 3: Cross multiply
    891.40x = 1,228.23 × 641.92
  4. Step 4: Simplify right side
    891.40x = 788,425.40
  5. Step 5: Solve for x
    x = 788,425.40/891.40
  6. Step 6: Final answer
    x = 884.48

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1.5x scale

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.