Answer:
d. 20
Step-by-step explanation:
Standard deviation is 4.5
Margin error for the problem is 2 hours
Probability 95%, that means that the siginficance level α is 1 – p
α = 1 – 0.95 = 0.05
margin of error (ME) can be defined as follows
ME = Z(α/2) * standard deviation/ √n
Where n is the sample size
Z(0.05/2) = Z(0.025)
Using a z table Z = 1.96
Now, replacing in the equation and find n
2 = 1.96 * 4.5/ √n
2 = 8.82/√n
√n = 8.82/2
√n = 4.41
n = 4.41^2
n = 19.44 ≈ 20
Answer:
x = 
7
Step-by-step explanation:
= 49
can equal 7 or -7
7 x 7 = 49. -7 x -7 = 49
To factor,
<h2>
[[[</h2>
1) First multiply coefficient of a² and constant no,
That is,
3×(-42)=-126
Since the<u> resultant no is negative</u>, you should find two such factors of 126 <u>which</u> <u>will give us the coefficient of a (=11)</u> on subracting those factors.
2) Find the factor
126=2×3×3×7
=18×7
18 and 17 are factors of 126
Also,18-7 =11.
So they are required factors for factoring,
<h2>
]]]</h2>
Once you have understood above steps you can solve on your own. All you need to do is split 11 into factors ,take common terms and you will get answer.
<u>Answer:</u>
3a²+11a-42
=3a²+(18-7)a -42
=3a²+18a-7a-42
=3a(a+6) -7(a+6)
=(a+6)(3a-7)
Answer:
It is b. ACB
Step-by-step explanation:
If draw a triangle, you would give the longest side to BC, because their angles equal 10
And you would give AC the shortest side of the triagle because their angles equal 7
And AB the last side because it is in between the other sides
Since AC have the smallest angle, they would have the smaller numbers
then that leaves B as the biggist number
