ANSWER
No real roots.
The roots are complex or imaginary.
EXPLANATION
The quadratic equation

has discriminant,

If the discriminant is less than zero , then the quadratic equation has no real roots.
The given discriminant is -9.
Since -9 is less than zero, it means the quadratic equation has complex or imaginary roots.
Percent decrease : (original number - new number) / original number...x 100
percent decrease = (25 - 18) / 25....x 100
percent decrease = 7/25 * 100
percent decrease = 700/25 = 28%
Your answer is f(y) > 0
A is your answer
Answer:
с. A matched pairs t-interval for a mean difference.
Step-by-step explanation:
With the sample, we will have possession of the sample mean and of the sample standard deviation, which means that the t-distribution will be used.
We want to find the mean number of back problems for each sample, and estimate the difference. Since the groups are similar, with only the positions in which they work being different, we have matched pairs. So the correct answer is given by option c.
Can you tell me the options first and the formula C=Y