Home / 1,315.50-1,970.60-621.20

Finding the Fourth Proportional to 1,315.50, 1,970.60 and 621.20

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Solution

The fourth proportional to 1,315.50, 1,970.60 and 621.20 is: 930.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,315.50 : 1,970.60 = 621.20 : x
  2. Step 2: Convert to fraction form
    1,315.50/1,970.60 = 621.20/x
  3. Step 3: Cross multiply
    1,315.50x = 1,970.60 × 621.20
  4. Step 4: Simplify right side
    1,315.50x = 1,224,123.76
  5. Step 5: Solve for x
    x = 1,224,123.76/1,315.50
  6. Step 6: Final answer
    x = 930.54

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1.5x scale

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.