Home / 509.78-703.40-299.91

Finding the Fourth Proportional to 509.78, 703.40 and 299.91

Calculator

Solution

The fourth proportional to 509.78, 703.40 and 299.91 is: 413.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.78 : 703.40 = 299.91 : x
  2. Step 2: Convert to fraction form
    509.78/703.40 = 299.91/x
  3. Step 3: Cross multiply
    509.78x = 703.40 × 299.91
  4. Step 4: Simplify right side
    509.78x = 210,957.44
  5. Step 5: Solve for x
    x = 210,957.44/509.78
  6. Step 6: Final answer
    x = 413.82

Related Problems

Find fourth proportional to 254.89, 351.70 and 149.96
Half scale
Find fourth proportional to 1,019.55, 1,406.81 and 599.82
Double scale
Find fourth proportional to 510.78, 704.78 and 300.91
Similar ratio
Find fourth proportional to 764.66, 1,055.10 and 449.87
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.