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Finding the Fourth Proportional to 904.89, 1,247.22 and 639.45

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Solution

The fourth proportional to 904.89, 1,247.22 and 639.45 is: 881.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    904.89 : 1,247.22 = 639.45 : x
  2. Step 2: Convert to fraction form
    904.89/1,247.22 = 639.45/x
  3. Step 3: Cross multiply
    904.89x = 1,247.22 × 639.45
  4. Step 4: Simplify right side
    904.89x = 797,534.83
  5. Step 5: Solve for x
    x = 797,534.83/904.89
  6. Step 6: Final answer
    x = 881.36

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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.