Home / 1,421.80-1,964.10-1,378.60

Finding the Fourth Proportional to 1,421.80, 1,964.10 and 1,378.60

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Solution

The fourth proportional to 1,421.80, 1,964.10 and 1,378.60 is: 1,904.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.80 : 1,964.10 = 1,378.60 : x
  2. Step 2: Convert to fraction form
    1,421.80/1,964.10 = 1,378.60/x
  3. Step 3: Cross multiply
    1,421.80x = 1,964.10 × 1,378.60
  4. Step 4: Simplify right side
    1,421.80x = 2,707,708.26
  5. Step 5: Solve for x
    x = 2,707,708.26/1,421.80
  6. Step 6: Final answer
    x = 1,904.42

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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.