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Finding the Fourth Proportional to 1,279.51, 1,765.71 and 720.08

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Solution

The fourth proportional to 1,279.51, 1,765.71 and 720.08 is: 993.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,279.51 : 1,765.71 = 720.08 : x
  2. Step 2: Convert to fraction form
    1,279.51/1,765.71 = 720.08/x
  3. Step 3: Cross multiply
    1,279.51x = 1,765.71 × 720.08
  4. Step 4: Simplify right side
    1,279.51x = 1,271,450.25
  5. Step 5: Solve for x
    x = 1,271,450.25/1,279.51
  6. Step 6: Final answer
    x = 993.70

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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.