What is the value of x? 6x - 2x = 16

The ratio of two numbers is 5 to 4. the sum of the numbers is 99. what number is the greater of the two numbers?

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

What is the area of the trapezoid shown ?