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Finding the Fourth Proportional to 1,280.16, 1,765.80 and 838.68

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Solution

The fourth proportional to 1,280.16, 1,765.80 and 838.68 is: 1,156.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.16 : 1,765.80 = 838.68 : x
  2. Step 2: Convert to fraction form
    1,280.16/1,765.80 = 838.68/x
  3. Step 3: Cross multiply
    1,280.16x = 1,765.80 × 838.68
  4. Step 4: Simplify right side
    1,280.16x = 1,480,941.14
  5. Step 5: Solve for x
    x = 1,480,941.14/1,280.16
  6. Step 6: Final answer
    x = 1,156.84

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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.