Answer:
hello misi how are you doing?
Answer:
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.28.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 7.6 - 0.1 = 7.5
The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Answer:
7/2
Step-by-step explanation:
2x=12-5....collectible like terms
2x=7
x=7/2...dividing both side by 2
Answer:
The value of x is 1 and y = -2
Step-by-step explanation:
y = 2x²- 3x - 1;
y = x - 3
2x²- 3x - 1 = x - 3
2x² - 3x - 1 - x + 3 = 0
2x² - 4x + 2 = 0
take 2 as common
2(x² - 2x + 1) = 0
x² - 2x + 1 = 0
x² - x - x + 1 = 0
x(x - 1) - 1(x - 1) = 0
(x - 1) (x - 1) = 0
x - 1 = 0 or x - 1 = 0
x = 1 or x = 1
Now,
y = x - 3
y = 1 - 3
y = - 2
Thus, The value of x is 1 and y is -2
<u>-TheUnknown</u><u>Scientist</u>