Answer:
I guess you want to find the relative frequencies:
In total, we have 396,651 children
in sample 1, we have 198,747 children, and of those, only 37 developed the disease.
This means that the vaccine is not effective in:
p = 37/198,747 = 0.00019
For the placebo, we have a sample of 197,904 children in total, and 111 of them developed the disease, then we have a probability of the placebo not being effective is:
p = 111/197,904 = 0.00056
So we can see that the difference is significant, meaning that the placebo is not effective in more than twice the cases where the vaccine is not effective.
Answer:
-2.31
Step-by-step explanation:
9/7 multiplied by (-9/5) is -2.31.
You first have to change the denominator into a common factor that each fraction has in common.
Then you just multiply them to get -2.31.
Answer:
-2
Step-by-step explanation:
We can use the slope formula
m = ( y2-y1)/(x2-x1)
= ( 8 -2)/(-4- -1)
= (8-2)/(-4+1)
= 6/-3
= -2
Answer:
NO SOLUTION
Step-by-step explanation:
Start by combining like terms: combine all the x terms and then all the constants:
8x + 2 = 8x - 4
Subtracting 8x from both sides results in 2 = -4, which is never true. Therefore, this equation has NO SOLUTION.
Answer:
There is no enough evidence that the viscosity is not 3000. The viscosity is not significantly different from 3000.
Step-by-step explanation:
We have to perform an hypothesis test on the mean.
The null and alternative hypothesis are:
![H_0: \mu=3000\\\\H_1:\mu\neq3000](https://tex.z-dn.net/?f=H_0%3A%20%5Cmu%3D3000%5C%5C%5C%5CH_1%3A%5Cmu%5Cneq3000)
The significance level is 0.05.
The mean of the sample is:
![M=(1/5)*(2781+2900+3013+2856+2888)=2887.6](https://tex.z-dn.net/?f=M%3D%281%2F5%29%2A%282781%2B2900%2B3013%2B2856%2B2888%29%3D2887.6)
The standard deviation of the sample is:
![s=\sqrt{\frac{1}{5-1}*[(2781-2887.6)^2 +(2900-2887.6)^2 +...]}=84.0](https://tex.z-dn.net/?f=s%3D%5Csqrt%7B%5Cfrac%7B1%7D%7B5-1%7D%2A%5B%282781-2887.6%29%5E2%20%2B%282900-2887.6%29%5E2%20%2B...%5D%7D%3D84.0)
The statistic t can be calculated as:
![t=\frac{M-\mu}{s} =\frac{2887.6-3000}{84} =-1.338](https://tex.z-dn.net/?f=t%3D%5Cfrac%7BM-%5Cmu%7D%7Bs%7D%20%3D%5Cfrac%7B2887.6-3000%7D%7B84%7D%20%3D-1.338)
The degrees of freedom are ![df=N-1=5-1=4](https://tex.z-dn.net/?f=df%3DN-1%3D5-1%3D4)
The P-value for t=-1.338 and df=4 is P=0.2519. The P-value is greater than the significance level, so it failed to reject the null hypothesis.
There is no enough evidence that the viscosity is not 3000.