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Finding the Fourth Proportional to 857.79, 1,278.89 and 805.49

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Solution

The fourth proportional to 857.79, 1,278.89 and 805.49 is: 1,200.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.79 : 1,278.89 = 805.49 : x
  2. Step 2: Convert to fraction form
    857.79/1,278.89 = 805.49/x
  3. Step 3: Cross multiply
    857.79x = 1,278.89 × 805.49
  4. Step 4: Simplify right side
    857.79x = 1,030,137.69
  5. Step 5: Solve for x
    x = 1,030,137.69/857.79
  6. Step 6: Final answer
    x = 1,200.92

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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.