Answer:
d. t distribution with df = 80
Step-by-step explanation:
Assuming this problem:
Consider independent simple random samples that are taken to test the difference between the means of two populations. The variances of the populations are unknown, but are assumed to be equal. The sample sizes of each population are n1 = 37 and n2 = 45. The appropriate distribution to use is the:
a. t distribution with df = 82.
b. t distribution with df = 81.
c. t distribution with df = 41.
d. t distribution with df = 80
Solution to the problem
When we have two independent samples from two normal distributions with equal variances we are assuming that
And the statistic is given by this formula:
Where t follows a t distribution with 
degrees of freedom and the pooled variance 
is given by this formula:
This last one is an unbiased estimator of the common variance 
So on this case the degrees of freedom are given by:
And the best answer is:
d. t distribution with df = 80
Answer:
103°
Step-by-step explanation:
The marked angles have the same measure, so ...
14x+7 = 12x +17
2x = 10 . . . . . subtract 12x+7
x = 5 . . . . . . . divide by 2
(14x +7)° = 77°
∠CEA is supplementary to the marked angles:
∠CEA = 180° -77°
∠CEA = 103°
Answer:
Step-by-step explanation:
Given that in a study of a weight loss program, 4 subjects lost an average of 48 lbs.
It is found that there is about a 32% chance of getting such results with a diet that has no effect.
The results do not appear to have statistical significance. The reasons are
1) Sample size of 4 is very small not even meeting the bare minimum
2) Sample of 4 cannot be taken to represent the population
3) Whether bias was there in the selection of sample is not known.
4) Std deviation is not considered which is very important while concluding results.
28-4=24-7=17$
this means alan spent $17 on lunch
Answer:
its f
Step-by-step explanation:
The solution x = 0 means that the value 0 satisfies the equation, so there is a solution. “No solution” means that there is no value, not even 0, which would satisfy the equation.
