Answer:
Check the explanation
Step-by-step explanation:
Let 
and 
be sample means of white and Jesse denotes are two random variables.
Given that both samples are having normally distributed.
Assume having with mean 
and having mean 
Also we have given the variance is constant
A)
We can test hypothesis as
For this problem
Test statistic is
Where
We have given all information for samples
By calculations we get
s=2.41
T=2.52
Here test statistic is having t-distribution with df=(10+7-2)=15
So p-value is P(t15>2.52)=0.012
Here significance level is 0.05
Since p-value is <0.05 we are rejecting null hypothesis at 95% confidence.
We can conclude that White has significant higher mean than Jesse. This claim we can made at 95% confidence.
Answer: X = 27
Step-by-step explanation: If we observe very closely, we have two similar triangles in the diagram. The first one is ABC and the other triangle is EDC. Also take note that angle ACB in the first triangle is equal in measurement to angle ECD (45 degrees) in the other triangle, (Opposite angles).
Hence in triangle ECD, we have identified two angles so far which are angle 2x + 10 and angle 45. Same applies to triangle ABC, we already have two angles which are, 3x - 10 and 45.
However angle D in the second triangle is equal in measurement to angle B in the first triangle
(Alternate angles).
Hence we have a third angle in triangle ABC which is
Angle B = 2x + 10.
Therefore 3x - 10 + (2x + 10) + 45 = 180
(Sum of angles in a triangle)
3x - 10 + 2x + 10 + 45 = 180
By collecting like terms we now have
3x + 2x = 180 + 10 - 10 - 45
5x = 135
Divide both sides by 5,
x = 27
So average is of the first 6 tests is 82 well that means
(test1 + test2+ test3+ test4 + test5+test6)/6 = 82
so now let do some cross multiplliying
test1 + test2 + test3 + test 4 + test5 +test6 = 82*6
test1 + test2 + test3 + test 4 + test5 +test6 = 492
now lets see if we can find that 7th test score
(test1 + test2 + test3 + test4 + test5 +test6 + test7)/7 = 80.5
So look we found test1 + test2 + test3 + test4 + test5 +test6 to be 492 so lets substitute.
(492 + test7 )/7 = 80.5
test7 = (80.5*7)-492 = 71.5
4 2/3. add the twos and keep the 2/3
) = -3.3
