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Finding the Fourth Proportional to 319.40, 438.42 and 283.64

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Solution

The fourth proportional to 319.40, 438.42 and 283.64 is: 389.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.40 : 438.42 = 283.64 : x
  2. Step 2: Convert to fraction form
    319.40/438.42 = 283.64/x
  3. Step 3: Cross multiply
    319.40x = 438.42 × 283.64
  4. Step 4: Simplify right side
    319.40x = 124,354.54
  5. Step 5: Solve for x
    x = 124,354.54/319.40
  6. Step 6: Final answer
    x = 389.33

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.