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Finding the Fourth Proportional to 690.79, 1,036.18 and 279.93

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Solution

The fourth proportional to 690.79, 1,036.18 and 279.93 is: 419.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.79 : 1,036.18 = 279.93 : x
  2. Step 2: Convert to fraction form
    690.79/1,036.18 = 279.93/x
  3. Step 3: Cross multiply
    690.79x = 1,036.18 × 279.93
  4. Step 4: Simplify right side
    690.79x = 290,057.87
  5. Step 5: Solve for x
    x = 290,057.87/690.79
  6. Step 6: Final answer
    x = 419.89

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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.