Home / 407.93-611.90-99.78

Finding the Fourth Proportional to 407.93, 611.90 and 99.78

Calculator

Solution

The fourth proportional to 407.93, 611.90 and 99.78 is: 149.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    407.93 : 611.90 = 99.78 : x
  2. Step 2: Convert to fraction form
    407.93/611.90 = 99.78/x
  3. Step 3: Cross multiply
    407.93x = 611.90 × 99.78
  4. Step 4: Simplify right side
    407.93x = 61,054.88
  5. Step 5: Solve for x
    x = 61,054.88/407.93
  6. Step 6: Final answer
    x = 149.67

Related Problems

Find fourth proportional to 203.97, 305.95 and 49.89
Half scale
Find fourth proportional to 815.87, 1,223.79 and 199.56
Double scale
Find fourth proportional to 408.93, 613.39 and 100.78
Similar ratio
Find fourth proportional to 611.90, 917.84 and 149.67
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.