Home / 1,415.50-2,123.55-428.39

Finding the Fourth Proportional to 1,415.50, 2,123.55 and 428.39

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Solution

The fourth proportional to 1,415.50, 2,123.55 and 428.39 is: 642.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,415.50 : 2,123.55 = 428.39 : x
  2. Step 2: Convert to fraction form
    1,415.50/2,123.55 = 428.39/x
  3. Step 3: Cross multiply
    1,415.50x = 2,123.55 × 428.39
  4. Step 4: Simplify right side
    1,415.50x = 909,704.93
  5. Step 5: Solve for x
    x = 909,704.93/1,415.50
  6. Step 6: Final answer
    x = 642.67

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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.