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Finding the Fourth Proportional to 1,379.42, 1,903.42 and 790

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Solution

The fourth proportional to 1,379.42, 1,903.42 and 790 is: 1,090.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.42 : 1,903.42 = 790 : x
  2. Step 2: Convert to fraction form
    1,379.42/1,903.42 = 790/x
  3. Step 3: Cross multiply
    1,379.42x = 1,903.42 × 790
  4. Step 4: Simplify right side
    1,379.42x = 1,503,701.80
  5. Step 5: Solve for x
    x = 1,503,701.80/1,379.42
  6. Step 6: Final answer
    x = 1,090.10

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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.