Step-by-step explanation:
Given - In selecting a sulfur concrete for roadway construction in regions that experience heavy frost, it is important that the chosen concrete has a low value of thermal conductivity in order to minimize subsequent damage due to changing temperatures. Suppose two types of concrete, a graded aggregate and a no-fines aggregate, are being considered for a certain road. The table below summarizes data on thermal conductivity from an experiment carried out to compare the two types of concrete.
Type ni xi si
Graded 42 0.486 0.187
No-fines 42 0.359 0.158
To find - a. Formulate the above in terms of a hypothesis testing problem.
b. Give the test statistic and its reference distribution (under the null hypothesis).
c. Report the p-value of the test statistic and use it to assess the evidence that this sample provides on the scientific question of difference in mean conductivity of the two materials at the 5% level of significance.
Proof -
a.)
Hypothesis testing problem :
H0 : There is significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.
H1 : There is no significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.
b)
Test statistic :
⇒Z(cal) = 3.3687
Z(tab) = 1.96
As Z (cal) > Z(tab)
So, we reject H0 at 5% Level of significance
p-value = 0.99962
Hence
There is significant difference in mean conductivity at the two materials.
Answer:
x = - 5, x = - 3
Step-by-step explanation:
Given
x² + 15 = - 8x ( add 8x to both sides )
x² + 8x + 15 = 0 ← in standard form
Consider the factors of the constant term (+ 15) which sum to give the coefficient of the x- term (+ 8)
The factors are 5 and 3, since
5 × 3 = 15 and 5 + 3= 8, thus
(x + 5)(x + 3) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 5 = 0 ⇒ x = - 5
x + 3 = 0 ⇒ x = - 3
Question 7: $3945
78,900÷100×5= 3,945
or 789,00×0.05= $3,945
Question 8: I think it may be $675.46 ( but I'm not sure)
$1010 is her annual insurance premium so to find one month we need to divide $1010 by 12
$1010÷12= $84.20
also her annual real estate tax is $938 and to find one month we need to divide this by 12 as well.
$938÷12=$78.20
and in order to find out her combined monthly payment we need to add them all together
$513.12+$84.16+$78.16= $675.46
Question 9: is False
Question 10: I don't know
Hope this helps
7x2.2 is 14.4 then you will need to multiply 3x2.2 then add them up
Answer:
It is proportional
Step-by-step explanation:
To determine if its proportional/non-proportional is by using ratios
so go line by line
p pine and k oak
12 pine to 44 oak
18 pine to 66 oak
24 pine to 88 oak
30 pine to 110 oak
Start with the first line
p= pine per k= oak
so obviously not numbers but to help mind you it just means the numbers will be put as p/k (to make life simpler)
Or pine over oak
Second Line
12/44 which reduces down to 3/11
Third Line
18/66 which reduces down to 3/11
Fourth line
24/88 which reduces down to 3/11
Fifth line
30/110 which reduces down to 3/11
In order to be proportional the ratios all have to be equivalent to each other
Therefore,
3/11 = 3/11 = 3/11 = 3/11
So this is proportional
