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Finding the Fourth Proportional to 772.09, 1,157.65 and 278.21

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Solution

The fourth proportional to 772.09, 1,157.65 and 278.21 is: 417.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    772.09 : 1,157.65 = 278.21 : x
  2. Step 2: Convert to fraction form
    772.09/1,157.65 = 278.21/x
  3. Step 3: Cross multiply
    772.09x = 1,157.65 × 278.21
  4. Step 4: Simplify right side
    772.09x = 322,069.81
  5. Step 5: Solve for x
    x = 322,069.81/772.09
  6. Step 6: Final answer
    x = 417.14

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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.