Home / 1,421.67-1,969.52-1,387.65

Finding the Fourth Proportional to 1,421.67, 1,969.52 and 1,387.65

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Solution

The fourth proportional to 1,421.67, 1,969.52 and 1,387.65 is: 1,922.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.67 : 1,969.52 = 1,387.65 : x
  2. Step 2: Convert to fraction form
    1,421.67/1,969.52 = 1,387.65/x
  3. Step 3: Cross multiply
    1,421.67x = 1,969.52 × 1,387.65
  4. Step 4: Simplify right side
    1,421.67x = 2,733,004.43
  5. Step 5: Solve for x
    x = 2,733,004.43/1,421.67
  6. Step 6: Final answer
    x = 1,922.39

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.