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Finding the Fourth Proportional to 1,280.21, 1,766.75 and 782.76

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Solution

The fourth proportional to 1,280.21, 1,766.75 and 782.76 is: 1,080.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.21 : 1,766.75 = 782.76 : x
  2. Step 2: Convert to fraction form
    1,280.21/1,766.75 = 782.76/x
  3. Step 3: Cross multiply
    1,280.21x = 1,766.75 × 782.76
  4. Step 4: Simplify right side
    1,280.21x = 1,382,937.32
  5. Step 5: Solve for x
    x = 1,382,937.32/1,280.21
  6. Step 6: Final answer
    x = 1,080.25

Related Problems

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Half scale
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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.