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:
Length of RU is 20 units.
Step-by-step explanation:
In ΔRSt and ΔRUT,
ST ≅ TU [Given]
RT ≅ RT [Reflexive property]
∠RTS ≅ ∠RTU [Both the angles are the right angles]
ΔRTS ≅ ΔRTU [By SAS property of congruence]
Therefore, RS ≅ RU [By CPCTC (corresponding parts of the congruent triangles are congruent]
8x = 6x + 5
8x - 6x = 5
2x = 5
x = 2.5
Length of RU = (6x + 5)
= 6(2.5) + 5
= 15 + 5
= 20
Length of RU is 20 units.
You haven’t supplied enough information to help you. The original question would have helped.
Answer:
It's 398
Step-by-step explanation.
Diameter of 8.
height of 12.
8 - .75 - .75= 6.5
6.5/2 = 3.25
3.25 x 3.25 x 12 x 3.14 = 397.995
round to the nearest whole number and you get
398
Take the diameter (8) an subtract is by both sides of the walls (0.75 each wall) that gives you 6.5. Take that 6.5 and half that, because you need to have the radius to solve volume problems, giving you 3.25. Then multiply 3.25 by 3.25 together ( I know it seems redundant but it just works easier this way) This gives you 10.5625. After that take 10.5625 then multiply it into 12, being the height, which gives you 126.75. Finally take 126.75 and multiply that into 3.14 (pie) giving you the answer.
