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Finding the Fourth Proportional to 855.38, 1,276.12 and 775.80

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Solution

The fourth proportional to 855.38, 1,276.12 and 775.80 is: 1,157.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.38 : 1,276.12 = 775.80 : x
  2. Step 2: Convert to fraction form
    855.38/1,276.12 = 775.80/x
  3. Step 3: Cross multiply
    855.38x = 1,276.12 × 775.80
  4. Step 4: Simplify right side
    855.38x = 990,013.90
  5. Step 5: Solve for x
    x = 990,013.90/855.38
  6. Step 6: Final answer
    x = 1,157.40

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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.