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Finding the Fourth Proportional to 840.68, 1,256.18 and 641.94

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Solution

The fourth proportional to 840.68, 1,256.18 and 641.94 is: 959.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.68 : 1,256.18 = 641.94 : x
  2. Step 2: Convert to fraction form
    840.68/1,256.18 = 641.94/x
  3. Step 3: Cross multiply
    840.68x = 1,256.18 × 641.94
  4. Step 4: Simplify right side
    840.68x = 806,392.19
  5. Step 5: Solve for x
    x = 806,392.19/840.68
  6. Step 6: Final answer
    x = 959.21

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.