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Finding the Fourth Proportional to 1,145.47, 1,718.21 and 279.78

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Solution

The fourth proportional to 1,145.47, 1,718.21 and 279.78 is: 419.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,145.47 : 1,718.21 = 279.78 : x
  2. Step 2: Convert to fraction form
    1,145.47/1,718.21 = 279.78/x
  3. Step 3: Cross multiply
    1,145.47x = 1,718.21 × 279.78
  4. Step 4: Simplify right side
    1,145.47x = 480,719.39
  5. Step 5: Solve for x
    x = 480,719.39/1,145.47
  6. Step 6: Final answer
    x = 419.67

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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.