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
Answer:Your left hand side evaluates to:
m+(−1)mn+(−1)m+(−1)mnp
and your right hand side evaluates to:
m+(−1)mn+(−1)m+np
After eliminating the common terms:
m+(−1)mn from both sides, we are left with showing:
(−1)m+(−1)mnp=(−1)m+np
If p=0, both sides are clearly equal, so assume p≠0, and we can (by cancellation) simply prove:
(−1)(−1)mn=(−1)n.
It should be clear that if m is even, we have equality (both sides are (−1)n), so we are down to the case where m is odd. In this case:
(−1)(−1)mn=(−1)−n=1(−1)n
Multiplying both sides by (−1)n then yields:
1=(−1)2n=[(−1)n]2 which is always true, no matter what n is
We are required to compare the magnitude for two earthquake intensity:
the larger intensity is 7.9
the smaller intensity is 3.7
thus the ratio of the intensity will be:
(larger intensity)/(smaller intensity)
=7.9/3.7
=2.135
~2
Thus we conclude that:
The larger earthquake's intensity was 2 times as great as the smaller earthquake's intensity.
Answer:
The numbers 180 and 0 would make the average 90
Step-by-step explanation:
we know that
To find the average of two numbers, add the numbers and then divide by two.
Let
x ----> one number
y ----> the other number
The average is equal to
(x+y)/2
For x=180 and y=0
the average is equal to
(180+0)/2=90
therefore
The numbers 180 and 0 would make the average 90