Home / 912.78-1,259.46-519.80

Finding the Fourth Proportional to 912.78, 1,259.46 and 519.80

Calculator

Solution

The fourth proportional to 912.78, 1,259.46 and 519.80 is: 717.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.78 : 1,259.46 = 519.80 : x
  2. Step 2: Convert to fraction form
    912.78/1,259.46 = 519.80/x
  3. Step 3: Cross multiply
    912.78x = 1,259.46 × 519.80
  4. Step 4: Simplify right side
    912.78x = 654,661.01
  5. Step 5: Solve for x
    x = 654,661.01/912.78
  6. Step 6: Final answer
    x = 717.22

Related Problems

Find fourth proportional to 456.39, 629.73 and 259.90
Half scale
Find fourth proportional to 1,825.56, 2,518.92 and 1,039.59
Double scale
Find fourth proportional to 913.78, 1,260.84 and 520.80
Similar ratio
Find fourth proportional to 1,369.17, 1,889.19 and 779.69
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.