Answer:
The probability is 0.04746
Step-by-step explanation:
Firstly, we calculate the z-score here
Mathematically;
z-score = x-mean/SD/√n
Where from the question;
x = 85, mean = 90 , SD = 15 and n = 25
Plugging these values into the equation, we have;
Z = (85-90)/15/√25 = -5/15/5 = -1.67
So the probability we want to calculate is ;
P(z > -1.67)
We use the standard normal distribution table for this;
P(z > -1.67) = 0.04746
Answer:
W { 2,3}
Step-by-step explanation:
The elements in W are the integers between 2 and 4 and including 2
That would be 2 and 3
W { 2,3}
Answer:
The probability is 9.80%.
Step-by-step explanation:
The u.s. senate consists of 100 members, 2 from each state.
A committee of five senators is formed.
P(at least one from Your state) = 1- 
= 1- 
= 
= 0.098
That is, 9.80%.
Answer:
We cannot say that the mean wake time are different before and after the treatment, with 98% certainty. So the zopiclone doesn't appear to be effective.
Step-by-step explanation:
The goal of this analysis is to determine if the mean wake time before the treatment is statistically significant. The question informed us the mean wake time before and after the treatment, the number of subjects and the standard deviation of the sample after treatment. So using the formula, we can calculate the confidence interval as following:
![IC[\mu ; 98\%] = \overline{y} \pm t_{0.99,n-1}\sqrt{\frac{Var(y)}{n}}](https://tex.z-dn.net/?f=IC%5B%5Cmu%20%3B%2098%5C%25%5D%20%3D%20%5Coverline%7By%7D%20%5Cpm%20t_%7B0.99%2Cn-1%7D%5Csqrt%7B%5Cfrac%7BVar%28y%29%7D%7Bn%7D%7D)
Knowing that
:
![IC[\mu ; 98\%] = 98.9 \pm 2.602\frac{42.3}{4} \Rightarrow 98.9 \pm 27.516](https://tex.z-dn.net/?f=IC%5B%5Cmu%20%3B%2098%5C%25%5D%20%3D%2098.9%20%5Cpm%202.602%5Cfrac%7B42.3%7D%7B4%7D%20%5CRightarrow%2098.9%20%5Cpm%2027.516)
![IC[\mu ; 98\%] = [71.387 ; 126,416]](https://tex.z-dn.net/?f=IC%5B%5Cmu%20%3B%2098%5C%25%5D%20%3D%20%5B71.387%20%3B%20126%2C416%5D)
Note that
so we cannot say, with 98% confidence, that the mean wake time before treatment is different than the mean wake time after treatment. So the zopiclone doesn't appear to be effective.
Answer:
Options A and B are true
(A) Before the authority increases tolls on any of the area bridges, it is required by law to hold public hearings at which objections to the proposed increase can be raised.
B. (B) Whenever bridge tolls are increased, the authority must pay a private contractor to adjust the automated toll-collecting machines.
Step-by-step explanation:
A. In a developed society, it's imperative for the authority to hold public hearings with stake holders to air their views before the tolls are increased, this would enable the authority to carry out proper assessment to know both the positive and negative impact of increasing the toll.
B. Increasing the tolls implies that there must be adjustment in the automated tolling machines and this would incur cost on the authority, this contract would be executed by private contractors.