Answer:
A, C, D
Step-by-step explanation:
Since 15 is a positive integer, it can be represented in positive situations.
15 students add classes to schedule. = 15
15 points are taken away. = -15
15 point are given. = 15
15 dollars has been added to your salary = 15
15 dollars have been taken from your salary = -15
Answer:
a) 
D. 9.74
b) 
B. 74
Step-by-step explanation:
Part a
We have the following dataset given:
69 74 75 62 70 93 64 69 61 88 67 77 87 90 66 91 77 63 82 82 71 74 76 65 83
We can begin calculating the sample mean with the following formula:

And replacing we got:

Now we can calculate the sample deviation with the following formula:

And after replace we got:

Part b
For this case we need to sort the value on increasing way:
[1] 61 62 63 64 65 66 67 69 69 70 71 74 74 75 76 77 77 82 82 83 87 88 90 91 93
And the median would be the value in the position 13 and we got:

A solution to a equation is when the variable is substituted fully. That makes the equation true.
The required probability of the coin landing tails up at least two times is 15/16.
Given that,
A fair coin is flipped seven times. what is the probability of the coin landing tails up at least two times is to be determined.
<h3>What is probability?</h3>
Probability can be defined as the ratio of favorable outcomes to the total number of events.
Here,
In the given question,
let's approach inverse operation,
The probability of all tails = 1 / 2^7 because there is only one way to flip these coins and get no heads.
The probability of getting 1 head = 7 /2^7
Adding both the probability = 8 / 2^7
Probability of the coin landing tails up at least two times = 1 - 8/2^7
= 1 - 8 / 128
= 120 / 128
= 15 / 16
Thus, the required probability of the coin landing tails up at least two times is 15/16.
Learn more about probability here:
brainly.com/question/14290572
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