Answer:
Train b is moving faster than a by 45 units an hour
Step-by-step explanation:
Answer: c)[50,60]
Step-by-step explanation:
The Empirical rule says that , About 68% of the population lies with the one standard deviation from the mean (For normally distribution).
We are given that , The heights of students in a class are normally distributed with mean 55 inches and standard deviation 5 inches.
Then by Empirical rule, about 68% of the heights of students lies between one standard deviation from mean.
i.e. about 68% of the heights of students lies between 
i.e. about 68% of the heights of students lies between 
Here, 
i.e. The required interval that contains the middle 68% of the heights. = [50,60]
Hence, the correct answer is c) (50,60)
Answer:
Option B) (7x+4)(7x+4) is correct
The product result in a perfect square trinomial is

Step-by-step explanation:
( using
)
( using
)


Therefore 
which is a perfect square trinomial
A trinomial is a perfect square trinomial if it can be factored into a binomial multiplied to itself. In a perfect square trinomial, two terms will be perfect squares.
Option B) (7x+4)(7x+4) is correct
The product result in a perfect square trinomial is
