1) Mean
The mean is given by the sum of the data divided by the number of data (4, in this case):

2) Standard deviation
The standard deviation is given by:

where

is the mean, that we already found at point 1), and N=4. Substituting data, we have:

Answer:
17) x=7
18) x= -26
19) x= -8
20) x= 6
Step-by-step explanation:
17) is congruent
18) is supplementary
19) is congruent
20) is congruent
Answer:
Step-by-step explanation:
Their point of intersection, assuming there is one, will be somewhere on the line y = x. This line, y = x, is the line of symmetry between a function and its inverse. So if the two do in fact intersect, it will be at some point on that line
21 friends.
44 - 2x = 2, where x is the number of friends Kristin has.
Subtract 2 on each side.
42 - 2x = 0
Add 2x on each side.
42 = 2x
Divide by 2 on each side.
42 / 2 = x
21 = x
Kristin has 21 friends.
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Based on the information given, it should be noted that the mean and standard deviation of Y will be 0.4899 and 0.699 respectively.
<h3>Calculating the mean.</h3>
Based on the information given, it should be noted that the probability distribution for y will be:
Y 0 1. 2
Probability 0.63. 0.25. 0.12
The mean of Y will be:
= (0 × 0.63) + (1 × 0.25) + (2 × 0.12)
= 0 + 0.25 + 0.25
= 0.49
The variance will be 0.4899. Therefore, the standard deviation will be:
= ✓0.4899
= 0.699
Learn more about mean on:
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