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Finding the Fourth Proportional to 919.12, 1,268.38 and 499.47

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Solution

The fourth proportional to 919.12, 1,268.38 and 499.47 is: 689.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.12 : 1,268.38 = 499.47 : x
  2. Step 2: Convert to fraction form
    919.12/1,268.38 = 499.47/x
  3. Step 3: Cross multiply
    919.12x = 1,268.38 × 499.47
  4. Step 4: Simplify right side
    919.12x = 633,525.73
  5. Step 5: Solve for x
    x = 633,525.73/919.12
  6. Step 6: Final answer
    x = 689.28

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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.