<span>3.4 - 2.8d + 2.8d - 1.3 = </span>3.4 - 1.3 - 2.8d + 2.8d = 3.4 <span>- 1.3 = 2,1
</span>
Answer:
x = –4
Step-by-step explanation:
x = –koef x / (2•koef x²)
Answer:
She needs a grade of 71 on her next text.
Step-by-step explanation:
Mean of a data-set:
The mean of a data-set is the sum of all values in the data-set divided by the number of values.
Tammy has scored 82, 78, and 93 on her previous three tests.
Thus, her grades are 82, 78, 93 and x, in which x is her grade in the fourth test.
There are 4 tests.
What score does she need on her next test so that her average (mean) is 81?
We have to find x when the mean is 81. So




She needs a grade of 71 on her next text.
Answer:


Step-by-step explanation:
For this case we have the following info given:
Weight before diet 180 125 240 150
Weight after diet 170 130 215 152
We define the random variable
and we can calculate the inidividual values:
D: 10, -5, 25, -2
And we can calculate the mean with this formula:

And the deviation with:

And after replace we got:

And the confidence interval for this case would be given by:

The degrees of freedom are given by:

For the 95% of confidence the value for the significance is
and the critical value would be
. And replacing we got:

