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Finding the Fourth Proportional to 900.75, 1,243.45 and 679.78

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Solution

The fourth proportional to 900.75, 1,243.45 and 679.78 is: 938.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    900.75 : 1,243.45 = 679.78 : x
  2. Step 2: Convert to fraction form
    900.75/1,243.45 = 679.78/x
  3. Step 3: Cross multiply
    900.75x = 1,243.45 × 679.78
  4. Step 4: Simplify right side
    900.75x = 845,272.44
  5. Step 5: Solve for x
    x = 845,272.44/900.75
  6. Step 6: Final answer
    x = 938.41

Related Problems

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Half scale
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Double scale
Find fourth proportional to 901.75, 1,244.83 and 680.78
Similar ratio
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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.