Answer:
Z=2
Step-by-step explanation:
Z8=16
Z=16/8
Z=2
Answer:
5 + 2x = 6
2x = 6-5
2x = 1
x = 0.5
n -3n = 14 -4n
-2n = 14-4n (since 4n is negative, change the sign to make it positive and then add 4n to both sides of the equation)
2n = 14
n = 7
7 (5a - 4) - 1 = 14 - 8a
35a - 28 - 1 = 14 -8a
35a -29 = 14 - 8a
43a = 43
a = 1
Answer:
B
Step-by-step explanation:
-5[ (x³+1)(x+4) ] = -5[ x³*(x+4) + 1*(x+4) ]
= -5 [ x³*x + x³*4 + 1*x + 1*4 ]
= -5 [ x⁴ + 4x³ + x + 4]
= -5*x⁴ + (-5)*4x³ + (-5)*x + (-5) * 4
= -5x⁴ - 20x³ - 5x - 20
We have been given that the distribution of the number of daily requests is bell-shaped and has a mean of 38 and a standard deviation of 6. We are asked to find the approximate percentage of lightbulb replacement requests numbering between 38 and 56.
First of all, we will find z-score corresponding to 38 and 56.


Now we will find z-score corresponding to 56.

We know that according to Empirical rule approximately 68% data lies with-in standard deviation of mean, approximately 95% data lies within 2 standard deviation of mean and approximately 99.7% data lies within 3 standard deviation of mean that is
.
We can see that data point 38 is at mean as it's z-score is 0 and z-score of 56 is 3. This means that 56 is 3 standard deviation above mean.
We know that mean is at center of normal distribution curve. So to find percentage of data points 3 SD above mean, we will divide 99.7% by 2.

Therefore, approximately
of lightbulb replacement requests numbering between 38 and 56.