Answer:
The line intercepts the y-axis and
Step-by-step explanation:
The intersection on the y-axis of a line is found to be .
That is, the intercept with the y-axis is the value of the function when x is equal to zero.
In this case we know the following points of the function:
x : -2 -1 0 1 2 3
y : 16 12 8 4 0 -4
Note that when then
.
Therefore the line intercepts the y-axis and
Answer:
4.924 years
Step-by-step explanation:
Lets denote X the lifetime of a tv tube (In years). X has distribution , with
unknown.
We know that P(X < 4) = 0.2. Using this data, we can find the value of throught standarization.
Lets call the standarization of X. Z has distribution N(0,1), and its cummulative function,
is tabulated. The values of
can be found in the attached file.
The value q such that doesnt appear on the table. We can find it by using the symmetry of the normal density function. The opposite of q, -q must verify that
, hence -q must be equal to 0.84. Thus, q = -0.84
But this value of q should match with the number , so we have
Thus, the expected lifetime of TV tubes is 4.924 years.
I hope this works for you!