Answer:
<u>22.67 ft</u> is the height of tree.
Step-by-step explanation:
Given:
Height of a person is 68 in and casts a shadow that is 54 in long.
At the same point, a tree casts a shadow that is 18 ft long.
Now, to find the height of tree.
Let the height of tree be 
If height of a person is 68 in he casts a shadow of 54 in.
So, 68 in is equivalent to 54 in.
Thus,
is equivalent to 18 ft.
Now, to get the height of tree by using cross multiplication method:

<em>By cross multiplying we get:</em>
<em />
<em />
<em>Dividing both sides by 54 we get:</em>


Therefore, the height of the tree is 22.67 ft.
Answer:
The calculated value of t= 0.1908 does not lie in the critical region t= 1.77 Therefore we accept our null hypothesis that fatigue does not significantly increase errors on an attention task at 0.05 significance level
Step-by-step explanation:
We formulate null and alternate hypotheses are
H0 : u1 < u2 against Ha: u1 ≥ u 2
Where u1 is the group tested after they were awake for 24 hours.
The Significance level alpha is chosen to be ∝ = 0.05
The critical region t ≥ t (0.05, 13) = 1.77
Degrees of freedom is calculated df = υ= n1+n2- 2= 5+10-2= 13
Here the difference between the sample means is x`1- x`2= 35-24= 11
The pooled estimate for the common variance σ² is
Sp² = 1/n1+n2 -2 [ ∑ (x1i - x1`)² + ∑ (x2j - x`2)²]
= 1/13 [ 120²+360²]
Sp = 105.25
The test statistic is
t = (x`1- x` ) /. Sp √1/n1 + 1/n2
t= 11/ 105.25 √1/5+ 1/10
t= 11/57.65
t= 0.1908
The calculated value of t= 0.1908 does not lie in the critical region t= 1.77 Therefore we accept our null hypothesis that fatigue does not significantly increase errors on an attention task at 0.05 significance level
Answer:
x=0, y=2. (0, 2).
Step-by-step explanation:
3x+2y=4
8x-3y=-6
---------------
3(3x+2y)=3(4)
2(8x-3y)=2(-6)
-----------------------
9x+6y=12
16x-6y=-12
----------------
25x=0
x=0/25
x=0
3(0)+2y=4
0+2y=4
2y=4-0
2y=4
y=4/2
y=2
Multiply (x/6) by 6 to get common denominators and then you can simplify equation to 6x=15, divide each side by 6 answer is x=2.5 or 5/2