Answer:
E(x)=0.15
V(x)=0.3075
S(x)=0.5545
Step-by-step explanation:
The mean of a discrete variable is calculated as:

where
are the values that the variable can take and
are their respective probabilities.
So, if we call x the number of defective transistors in cartons, we can calculate the mean E(x) as:

Because there are 0 defective transistor with a probability of 0.92, 1 defective transistor with a probability of 0.03, 2 defective transistors with a probability of 0.03 and 3 defective transistors with a probability of 0.01.
At the same way, the variance V(x) is calculated as:

Where 
So, the variance V(x) is equal to:

Finally, the standard deviation is calculated as:

Answer:
b - 8
Step-by-step explanation:
3b - 2b = b
-6 - 2 = 8
= b - 8
Answer:

Step-by-step explanation:







Given:
Dimensions of rectangular garden are (-7x-3) feet by (9x+2) feet.
Cost of oak fencing = $11 per foot
To find:
The cost of total oak fencing around her garden.
Solution:
Let,
Length of the garden, l = (-7x-3) feet
Width of the garden, w = (9x+2) feet




So, the perimeter of garden is (4x-2) fee.
Cost of oak fencing is $11 per foot. So, total cost is

Therefore, the total cost of oak fencing is 44x-22x.
The answer to yo question is 4