Answer:
And we are 95% confident that the true difference means are between 
Step-by-step explanation:
We know the following info:
sample mean for group 1
sample mean for group 2
sample standard deviation for group 1
sample standard deviation for group 2
sample size group 1
sample size group 2
We want to find a confidence interval for the difference of means and the correct formula to do this is:
Now we just need to find the critical value. The confidence level is 0.95 then the significance is 
and 
. The degrees of freedom are given by:
The critical value for this case would be :
And replacing into the confidence interval formula we got:
And we are 95% confident that the true difference means are between
Use this formula.
and solution is:［（18！）/（6！×（18-6）！）］×（1/2）^6×（1-1/2）^（18-6）≈0.0781604
7.8%
Step-by-step explanation:
Use the sine and cosine trig functions
21) cos(52)=13/x
x=13/cos(52)
x=21.1
22) sin(75)=6/x
x=6/sin(75)
x=6.2
The bottom 2 i’m pretty sure, sorrry if it’s wrong
First you simply have to substitute 2 in replace of all the a's, and -2 in replace of all of the b's
4((2)2+2(-2))
Then you want to follow the order of operations, PEMDAS (Parantheses-Exponent-Multiplication-Division-Addition-Subtraction), and multiply within the parantheses.
4(4+(-4))
Next you will add within the parantheses (So add the 4 and -4 together)
4(0)
Lastly multiply
0
Your answer is 0
Hope this helps!
