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:
Step-by-step explanation:
Line is passing through the point 
and has slope (m) = - 9
General equation of line in point slope form is given as:
Therefore
This is the required equation of line in point slope form.
Answer:
He needs $15 more
Step-by-step explanation:
since each ticket costs $10 dollars, and there is 6 tickets, we need to multiply 10 x 6 to get the total cost of all tickets
10 x 6 = $60
To find how much more money he needs to buy all tickets, we need to subtract $45 from the total cost of tickets, which is $60
$60 - $45 = $15
Hope you understand this explanation!
Answer:
A 1.3
Step-by-step explanation:
probabilities lie between 0 and 1 and cannot be more or less
1) This is not an arithmetic sequence because it has n².
2) To find 5 first terms of this sequence, you can simply substitute n with 1,2,3,4, and 5, and calculate values of a(1),a(2), a(3), a(4) and a(5).
a(n) = 3n²- 1
n=1 a=3*1² - 1 = 3-1=2
n=2 a=3*2² - 1 = 11
n=3 a=3*3² - 1 =26
n=4 a=3*4² - 1 = 47
n=5 a=3*5² -1 = 74
2,11,26,47,74
Answer C. 2,11,26,47,74.
