Given the dataset

We start by computing the average:

We compute the difference bewteen each element and the average:

We square those differences:

And take the average of those squared differences: we sum them

And we divide by the number of elements:

Finally, we take the square root of this quantity and we have the standard deviation:

Answer: Its 45*
Step-by-step explanation:
Answer:
$100
Step-by-step explanation:
she bought food using that money, 70$ worth of it plus she still has 30
Answer:
300 seconds
Step-by-step explanation:
The first dog run at v₁ = 15 m/sec the second one run at v₂ = 12 m/sec
we know that d = v*t then t = d/v
Then the first dog will take 300/ 12 = 25 seconds to make a turn
The second will take 300 / 15 = 20 seconds to make a turn
Then the first dog in 12 turns 12*25 will be at the start point, and so will the second one at the turn 15.
To check first dog 12 * 25 = 300
And the second dog 15 * 20 = 300
That means that time required for the two dogs to be at the start point together is
300 seconds, in that time the first dog finished the 12 turns, and the second had ended the 15.
Another procedure to solve this problem is as follows:
between 12 m/sec and 15 m/sec the minimum common multiple is 300 ( 300 is the smaller number that accept 12 and 15 as factors 12*15 = 300) Then when time arrives at 300 seconds the two dogs will be again in the starting point
So what you would do is put in the 4 where ever you see an x. so it would look like -3(4)+9y=-57 then you solve for y. and the answer is -5. Make sense?