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Finding the Fourth Proportional to 920.40, 1,268.64 and 609.36

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Solution

The fourth proportional to 920.40, 1,268.64 and 609.36 is: 839.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.40 : 1,268.64 = 609.36 : x
  2. Step 2: Convert to fraction form
    920.40/1,268.64 = 609.36/x
  3. Step 3: Cross multiply
    920.40x = 1,268.64 × 609.36
  4. Step 4: Simplify right side
    920.40x = 773,058.47
  5. Step 5: Solve for x
    x = 773,058.47/920.40
  6. Step 6: Final answer
    x = 839.92

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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.