Answer:
x = -6
x = 2
Step-by-step explanation:
x² + 4 - 12 = 0
= (x + 6)(x - 2)
x + 6 = 0
x = -6
x - 2 = 0
x = 2
Answer:
5040
Step-by-step explanation:
7!
= 1 × 2 × 3 × 4 × 5 × 6 × 7
= 5040
Answer:


![Interval = [666.78, 781.62]](https://tex.z-dn.net/?f=Interval%20%3D%20%5B666.78%2C%20781.62%5D)
Step-by-step explanation:
Given
The data for 25 undergraduates
Solving (a): Range and Standard deviation
The range is:

From the dataset:


So:



The standard deviation is:

First, calculate the mean



So, the standard deviation is:




Solving (b): The interval of the 95% of the observation.
Using the emperical rule, we have:
![Interval = [\bar x - 2*\sigma, \bar x+ 2*\sigma]](https://tex.z-dn.net/?f=Interval%20%3D%20%5B%5Cbar%20x%20-%202%2A%5Csigma%2C%20%5Cbar%20x%2B%202%2A%5Csigma%5D)
![Interval = [724.2 - 2*28.71, 724.2 + 2*28.71]](https://tex.z-dn.net/?f=Interval%20%3D%20%5B724.2%20-%202%2A28.71%2C%20724.2%20%2B%202%2A28.71%5D)
![Interval = [666.78, 781.62]](https://tex.z-dn.net/?f=Interval%20%3D%20%5B666.78%2C%20781.62%5D)
The answer is 80 because the answer for all three sides should be 180