Home / 779.64-1,074.09-645.99

Finding the Fourth Proportional to 779.64, 1,074.09 and 645.99

Calculator

Solution

The fourth proportional to 779.64, 1,074.09 and 645.99 is: 889.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.64 : 1,074.09 = 645.99 : x
  2. Step 2: Convert to fraction form
    779.64/1,074.09 = 645.99/x
  3. Step 3: Cross multiply
    779.64x = 1,074.09 × 645.99
  4. Step 4: Simplify right side
    779.64x = 693,851.40
  5. Step 5: Solve for x
    x = 693,851.40/779.64
  6. Step 6: Final answer
    x = 889.96

Related Problems

Find fourth proportional to 389.82, 537.05 and 323.00
Half scale
Find fourth proportional to 1,559.28, 2,148.18 and 1,291.98
Double scale
Find fourth proportional to 780.64, 1,075.47 and 646.99
Similar ratio
Find fourth proportional to 1,169.46, 1,611.14 and 968.99
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.