Answer: 40%
Step-by-step explanation:
Since 20 beings preferred Freon juice to all other juices and there were 50 people that were surveyed, the percentage of those that preferred Freon Juice will be:
= Those that preferred Freon Juice / Total number surveyed. × 10
= 20/50 × 100
= 40%
Answer:
(a+2)(b+2) = 4
Step-by-step explanation:
We are given the following quadratic equation:

Let a a and b be the solution of the given quadratic equation.
Solving the equation:

We have to find the value of (a+2)(b+2).
Putting the values:

Answer:

Step-by-step explanation:
The confidence interval for the population mean x can be calculated as:

Where x' is the sample mean, s is the population standard deviation, n is the sample size and
is the z-score that let a proportion of
on the right tail.
is calculated as: 100%-99%=1%
So, 
Finally, replacing the values of x' by 308, s by 17, n by 15 and
by 2.576, we get that the confidence interval is:
