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Finding the Fourth Proportional to 1,220.51, 1,684.32 and 689.42

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Solution

The fourth proportional to 1,220.51, 1,684.32 and 689.42 is: 951.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,220.51 : 1,684.32 = 689.42 : x
  2. Step 2: Convert to fraction form
    1,220.51/1,684.32 = 689.42/x
  3. Step 3: Cross multiply
    1,220.51x = 1,684.32 × 689.42
  4. Step 4: Simplify right side
    1,220.51x = 1,161,203.89
  5. Step 5: Solve for x
    x = 1,161,203.89/1,220.51
  6. Step 6: Final answer
    x = 951.41

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Double scale
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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.