Home / 1,121.24-1,681.81-390.98

Finding the Fourth Proportional to 1,121.24, 1,681.81 and 390.98

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Solution

The fourth proportional to 1,121.24, 1,681.81 and 390.98 is: 586.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.24 : 1,681.81 = 390.98 : x
  2. Step 2: Convert to fraction form
    1,121.24/1,681.81 = 390.98/x
  3. Step 3: Cross multiply
    1,121.24x = 1,681.81 × 390.98
  4. Step 4: Simplify right side
    1,121.24x = 657,554.07
  5. Step 5: Solve for x
    x = 657,554.07/1,121.24
  6. Step 6: Final answer
    x = 586.45

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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.