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 
196.9-57.5= 139.4 million sq miles is water
Probability is described as predicted outcomes over total outcomes so, 139.4/196.9
Answer:
Mparallel = 1
Step-by-step explanation:
Hope this helps!
Answer:
x = 7
Step-by-step explanation:
-3 + 2x = 11
(group like terms)
2x = 11 + 3
2x = 14
(divide both sides by 2 to make x stand alone)
2x/2 = 14/2
x = 7
I believe it’s 72 I hope it’s right