Home / 828.35-1,239.86-437.80

Finding the Fourth Proportional to 828.35, 1,239.86 and 437.80

Calculator

Solution

The fourth proportional to 828.35, 1,239.86 and 437.80 is: 655.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.35 : 1,239.86 = 437.80 : x
  2. Step 2: Convert to fraction form
    828.35/1,239.86 = 437.80/x
  3. Step 3: Cross multiply
    828.35x = 1,239.86 × 437.80
  4. Step 4: Simplify right side
    828.35x = 542,810.71
  5. Step 5: Solve for x
    x = 542,810.71/828.35
  6. Step 6: Final answer
    x = 655.29

Related Problems

Find fourth proportional to 414.18, 619.93 and 218.90
Half scale
Find fourth proportional to 1,656.70, 2,479.72 and 875.60
Double scale
Find fourth proportional to 829.35, 1,241.36 and 438.80
Similar ratio
Find fourth proportional to 1,242.53, 1,859.79 and 656.70
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.