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Finding the Fourth Proportional to 690.77, 1,036.56 and 279.84

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Solution

The fourth proportional to 690.77, 1,036.56 and 279.84 is: 419.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.77 : 1,036.56 = 279.84 : x
  2. Step 2: Convert to fraction form
    690.77/1,036.56 = 279.84/x
  3. Step 3: Cross multiply
    690.77x = 1,036.56 × 279.84
  4. Step 4: Simplify right side
    690.77x = 290,069.55
  5. Step 5: Solve for x
    x = 290,069.55/690.77
  6. Step 6: Final answer
    x = 419.93

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.