To find the equation of the line with a given point and slope, we can fill them into the point-slope formula. The point-slope formula is y-y₁=m(x-x₁).

y-4=-3(x-(-4)) [multiply]

y-4=-3(x+4)

Another equation could be slope-intercept form. It is y=mx+b.

y-4=-3(x+4) [distribute]

y-4=-3x-12 [add both sides by 4]

y=-3x-8

Now, we know that the equation is y=-3x-8 or y-4=-3(x+4).

3 0

3 years ago

Given that events A and B are mutually exclusive, i.e., A?B = ? and P(A?B) =0, and that P(A)=0.7 and P(B)=0.2, find P(A or B).

TEA [102]

Answer:

Step-by-step explanation:

i use d relationship between them

7 0

3 years ago

The waking time of a student under common conditions is normally distributed with mean of 30 hours and a standard deviation of 5

Elina [12.6K]

Answer:

If the walking time is greater than or equal to 38.225 hours, than it exceeds 95% probability that is lie in top 5%.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 30 hours

Standard Deviation, σ = 5 hours

We are given that the distribution of waking time is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

We have to find the value of x such that the probability is 0.95

$P( X < x) = P( z < \displaystyle\frac{x - 30}{5})=0.95$

Calculation the value from standard normal z table, we have,

$\displaystyle\frac{x - 30}{5} = 1.645\\\\x = 38.225$

Thus, if the walking time is greater than or equal to 38.225 hours, than it exceeds 95% probability that is lie in top 5%.

4 0

3 years ago