The best unit for measuring the length of an eyelash is millimeters
Using the mean concept, it is found that we will need 15 more points to bring up his average up to 90%.
The mean of a data-set is the <u>sum of all observations divided by the number of observations</u>.
In this problem:
- In the first 5 observations, total of 21 out of 25 points, hence the mean for these observations is
. - In the next n observations, mean of 1.
Hence, the mean is:

We want the mean to be of 0.9, thus:





3 more testes are need, each worth 5 points, hence, 15 more points are needed to bring up his average up to 90%.
A similar problem is given at brainly.com/question/25323941
4 + 3s – 9s = 22
4 - 6s = 22
-6s = 18
-6s/-6 = 18/-6
s = -3
S would equal -3
Best Regards, Mike
The HL Postulate
You know that the two hypotenuses are congruent and that the two triangles each contain a shared segment in the middle (so by the reflexive property they are congruent). You have two congruent hypotenuses and two congruent legs, so you can conclude congruency by HL.
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