Home / 369.20-509.46-221.78

Finding the Fourth Proportional to 369.20, 509.46 and 221.78

Calculator

Solution

The fourth proportional to 369.20, 509.46 and 221.78 is: 306.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    369.20 : 509.46 = 221.78 : x
  2. Step 2: Convert to fraction form
    369.20/509.46 = 221.78/x
  3. Step 3: Cross multiply
    369.20x = 509.46 × 221.78
  4. Step 4: Simplify right side
    369.20x = 112,988.04
  5. Step 5: Solve for x
    x = 112,988.04/369.20
  6. Step 6: Final answer
    x = 306.03

Related Problems

Find fourth proportional to 184.60, 254.73 and 110.89
Half scale
Find fourth proportional to 738.40, 1,018.92 and 443.56
Double scale
Find fourth proportional to 370.20, 510.84 and 222.78
Similar ratio
Find fourth proportional to 553.80, 764.19 and 332.67
1.5x scale

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.