Home / 855.20-1,282.80-611.20

Finding the Fourth Proportional to 855.20, 1,282.80 and 611.20

Calculator

Solution

The fourth proportional to 855.20, 1,282.80 and 611.20 is: 916.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.20 : 1,282.80 = 611.20 : x
  2. Step 2: Convert to fraction form
    855.20/1,282.80 = 611.20/x
  3. Step 3: Cross multiply
    855.20x = 1,282.80 × 611.20
  4. Step 4: Simplify right side
    855.20x = 784,047.36
  5. Step 5: Solve for x
    x = 784,047.36/855.20
  6. Step 6: Final answer
    x = 916.80

Related Problems

Find fourth proportional to 427.60, 641.40 and 305.60
Half scale
Find fourth proportional to 1,710.40, 2,565.60 and 1,222.40
Double scale
Find fourth proportional to 856.20, 1,284.30 and 612.20
Similar ratio
Find fourth proportional to 1,282.80, 1,924.20 and 916.80
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.