Plz help me quickly
1 answer:
You might be interested in
Answer:
The sample mean is
b.3.55
The margin of error is
0.32
Step-by-step explanation:
Deep explanation about a confidence interval
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.
The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.
In this problem:
The deep explanation is not that important.
We just have to recognize that the interval has a lower end and an upper end. The distance from both the upper and the lower end to the mean is M. This means that the sample mean is the halfway point between the lower end and the upper end.
The margin of error is the distance of these two points(lower and upper end) to the mean.
In our interval
Lower end: 3.23
Upper end: 3.87
Sample mean
So the correct answer is:
b.3.55
The margin of error is
3.87 - 3.55 = 3.55 - 3.23 = 0.32
Answer:
Options: A, B, and C correctly solve for x.
Step-by-step explanation:
A).
=
Multiplying both sides by 2 gives;
5x = 15
x = 15 ÷ 5 = 3
∴ This option correctly solve for x.
B).
x + = 7
x = 7 - =
∴ This option correctly solve for x.
C).
x + 3 =
x =
But the option give x as 5/6 hence this option does not correctly solve for x.
D).
5x = 11/2
x = 11/2 ÷ 5 = 11/2 × 1/5 = 11/10
But the option gives x as 10/11 so it does not correctly solve for x.
Answer:
y ≤ 2x -2 Option C.
Step-by-step explanation:
Equation of the dotted line which passes through (3,0) and (0,8) will be
y = mx+C
m = = -1
and C = 3
So equation will be y = x + 3
But shaded blue part is above the dotted line so inequality will be y> -x +3
Equation of the second solid line which passes through ( 0,-2) and (1,0) will be
y = mx + C
m = =
= 2
and C = -2
So equation of the line will be y = 2x - 2
But shaded yellow part is below the solid line.
So inequality will be
y ≤ 2x -2
Option C. is the answer.