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Finding the Fourth Proportional to 900.78, 1,243.44 and 679.79

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Solution

The fourth proportional to 900.78, 1,243.44 and 679.79 is: 938.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    900.78 : 1,243.44 = 679.79 : x
  2. Step 2: Convert to fraction form
    900.78/1,243.44 = 679.79/x
  3. Step 3: Cross multiply
    900.78x = 1,243.44 × 679.79
  4. Step 4: Simplify right side
    900.78x = 845,271.86
  5. Step 5: Solve for x
    x = 845,271.86/900.78
  6. Step 6: Final answer
    x = 938.38

Related Problems

Find fourth proportional to 450.39, 621.72 and 339.89
Half scale
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Double scale
Find fourth proportional to 901.78, 1,244.82 and 680.79
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.