Answer:

Step-by-step explanation:
The fraction is the equivalent of ...

and the distributive property applies.

Answer:
-6
Step-by-step explanation:
Are you sure that z + 2+ z is correct? x and y do not appear here.
z + 2+ z simplifies to 2z + 2, and so, if z = -4, z + 2+ z has the value
2(-4) + 2, or -6.
Answer:
Significance of the mean of a probability distribution.
Step-by-step explanation:
- The mean of a probability distribution is the arithmetic average value of a random variable having that distribution.
- For a discrete probability distribution, the mean is given by,
, where P(x) is the probabiliy mass function. - For a continuous probability distribution, the mean s given by,
, where f(x) is the probability density function. - Mean is a measure of central location of a random variable.
- It is the weighted average of the values that X can take, with weights given by the probability density function.
- The mean is known as expected value or expectation of X.
- An important consequence of this is that the mean of any symmetric random variable (continuous or discrete) is always on the axis of symmetry of the distribution.
- For a continuous random variable, the mean is always on the axis of symmetry of the probability density function.
Step-by-step explanation:
r = 7x + 7y
8 = 7x + 7 ×2
8 = 7x + 14
7x = 14 - 8
7x = 6
X = 6 / 7