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Finding the Fourth Proportional to 1,288.90, 1,777.89 and 791.35

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Solution

The fourth proportional to 1,288.90, 1,777.89 and 791.35 is: 1,091.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.90 : 1,777.89 = 791.35 : x
  2. Step 2: Convert to fraction form
    1,288.90/1,777.89 = 791.35/x
  3. Step 3: Cross multiply
    1,288.90x = 1,777.89 × 791.35
  4. Step 4: Simplify right side
    1,288.90x = 1,406,933.25
  5. Step 5: Solve for x
    x = 1,406,933.25/1,288.90
  6. Step 6: Final answer
    x = 1,091.58

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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.