Answer:
B. z Subscript alpha divided by 2 zα/2 = 1.96.
Step-by-step explanation:
We are given that we want to construct a confidence interval. For this, the summary statistics for randomly selected weights of newborn girls:
n = 236, 
= 30.3 hg, s = 7.2 hg. The confidence level is 95%.
As we can clearly see here that the population standard deviation is unknown and the sample size is also very large.
It has been stated that when the population standard deviation is unknown, we should use t-distribution but since the sample size is very large so we can use z distribution also as it is stated that at very large samples; the t-distribution corresponds to the z-distribution.
Here, 
= level of significance = 1 - 0.95 = 0.05 or 5%
= 0.025 or 2.5%
So, the value of 
in the z table is given as 1.96 with a 2.5% level of significance.
Answer:
(2, 2 )
Step-by-step explanation:
To find a solution, choose any value for x, substitute into the equation and solve for y.
Choose x = 2, then
- 2 - 4y = - 10 ( add 2 to both sides )
- 4y = - 8 ( divide both sides by - 4 )
y = 2
Thus (2, 2 ) is a solution to the equation
Given:
1 set requires 4 couples 8 dancers.
Total number of people at a square dance = 250.
To find:
The greatest number of sets possible at the dance.
Solution:
We have,
Total people = 250
1 set = 8 people.
Number of possible sets cannot be a decimal or fraction value. So, approx. the value to the preceding integer.
Therefore, the number of possible sets at the dance is 31.
Answer:
x = 1, y = 1
Step-by-step explanation:
3x - 4y = -1
5x + 2y = 7
If we multiply the whole second equation by 2, we get:
10x + 4y = 14
Adding this to the first equation:
10x + 4y + 3x - 4y = 14 - 1
13x = 13
x = 1
Applying this to the second equation:
5 (1) + 2y = 7
2y = 2
y = 1
You start by finding two points on the line. In this case, (-4,1) and (-2,2) will do.
To get from (-4,1) to (-2,2), you need to go “up 1, right 2” which gives you a slope of m = 1/2
Next you need the b-value, which comes from the y-intercept of (0,3). The b-value is 3.
Putting the slope and b-value into y=mx+b, you have y = 1/2 x + 3.
