Home / 893.78-1,233.78-645.20

Finding the Fourth Proportional to 893.78, 1,233.78 and 645.20

Calculator

Solution

The fourth proportional to 893.78, 1,233.78 and 645.20 is: 890.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    893.78 : 1,233.78 = 645.20 : x
  2. Step 2: Convert to fraction form
    893.78/1,233.78 = 645.20/x
  3. Step 3: Cross multiply
    893.78x = 1,233.78 × 645.20
  4. Step 4: Simplify right side
    893.78x = 796,034.86
  5. Step 5: Solve for x
    x = 796,034.86/893.78
  6. Step 6: Final answer
    x = 890.64

Related Problems

Find fourth proportional to 446.89, 616.89 and 322.60
Half scale
Find fourth proportional to 1,787.56, 2,467.56 and 1,290.40
Double scale
Find fourth proportional to 894.78, 1,235.16 and 646.20
Similar ratio
Find fourth proportional to 1,340.67, 1,850.67 and 967.80
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.