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:
1. x= -4
2. x= 18
3. x= -15
4. x = 6
Step-by-step explanation:
Use relationship of angles to create equations and solve for x
If we divide the area we have to cover by the area of a piece, we will get the number of pieces needed:

Step-by-step explanation:
I am not allowed to answer more than 3 questions. So I will do the first 3.
15a. i) (2/3) = 4/9
ii) (2/3) = 8/27
iii) (2/3) = 16/81
b. The product is small because you are finding the fraction of a fraction.
16. Compared to the factors, the product is less than each fraction. This is because, as stated above, you are trying to find a fraction (a part of the whole) of another fraction. When you multiply a whole number by a fraction, the whole number decreases. The same applies to a fraction.
17a. 0.4 × 0.3 = 0.12
b. 0.4 = 4/10 = 2/5
0.3 = 3/10
3/10 × 2/5 = 6/50
Answer:
f
(
x
)
=
5
x
2
−
2
x
+
3
g
(
x
)
=
4
x
2
+
7
x
−
5
f
(
g
(
x
)
)
=
5
(
4
x
2
+
7
x
−
5
)
2
−
2
(
4
x
2
+
7
x
−
5
)
+
3
=
80
x
4
+
280
x
3
+
45
x
2
−
350
x
+
125
−
8
x
2
−
14
x
+
10
+
3
=
80
x
4
+
280
x
3
+
45
x
2
−
8
x
2
−
350
x
−
14
x
+
125
+
10
+
3
f
(
g
(
x
)
)
=
80
x
4
+
280
x
3
+
37
x
2
−
364
x
+
138
The answer is
f
(
g
(
x
)
)
=
80
x
4
+
280
x
3
+
37
x
2
−
364
x
+
138
.
Step-by-step explanation: