Answer:
a)
b)
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Part a
Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability like this:
And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.
Part b
For this case we select a sample size of n =32. Since the distribution for X is normal then the distribution for the sample mean is given by:
And the new z score would be:
Step-by-step explanation:
(a-b)^2=a^2-2ab+b^2
X^2-2(X)(5)+5^2
Ans C
X^2-10X+25
Answer:
Right of -7 and left of -1
Step-by-step explanation:
-7 is in the left and -4 is in the right
-7<4
-4 in the left and -1 in the right
-4<-1
just use directions
Your answer is C. Hope this help :D