Home / 1,290.36-1,782.10-1,217.40

Finding the Fourth Proportional to 1,290.36, 1,782.10 and 1,217.40

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Solution

The fourth proportional to 1,290.36, 1,782.10 and 1,217.40 is: 1,681.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290.36 : 1,782.10 = 1,217.40 : x
  2. Step 2: Convert to fraction form
    1,290.36/1,782.10 = 1,217.40/x
  3. Step 3: Cross multiply
    1,290.36x = 1,782.10 × 1,217.40
  4. Step 4: Simplify right side
    1,290.36x = 2,169,528.54
  5. Step 5: Solve for x
    x = 2,169,528.54/1,290.36
  6. Step 6: Final answer
    x = 1,681.34

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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.