Answer:
Yes, this is a valid inference because she took a random sample of the neighborhood.
Step-by-step explanation:
As we can see, Sue's survey was perfectly random and without any prejudice.
18% of the families, according to her research, would volunteer at the shelter. According to her, 18% of the local households should be required to volunteer at the animal shelter.
Therefore, given that she chose a representative sample of the area, her conclusion is valid.
Answer:
A) increases
Step-by-step explanation:
5/x + 5
suppose x = 5; then 5/5 + 5 = 1 + 5 = 6
x = 2; then 5/2 + 5 = 2.5 + 5 = 7.5
x = 1 ;then 5/1 + 5 = 5 + 5 = 10
So when x value decreases from a large positive number to a small positive number, 5/x + 5 increases
Answer:
The answer is below
Step-by-step explanation:
1)
mean (μ) = 12, SD(σ) = 2.3, sample size (n) = 65
Given that the confidence level (c) = 90% = 0.9
α = 1 - c = 0.1
α/2 = 0.05
The z score of α/2 is the same as the z score of 0.45 (0.5 - 0.05) which is equal to 1.65
The margin of error (E) is given as:
The confidence interval = μ ± E = 12 ± 0.47 = (11.53, 12.47)
2)
mean (μ) = 23, SD(σ) = 12, sample size (n) = 45
Given that the confidence level (c) = 88% = 0.88
α = 1 - c = 0.12
α/2 = 0.06
The z score of α/2 is the same as the z score of 0.44 (0.5 - 0.06) which is equal to 1.56
The margin of error (E) is given as:
The confidence interval = μ ± E = 23 ± 2.8 = (22.2, 25.8)
Answer:
notebook: $2.5
pen: $1.5
part B, he can buy 3 pens
Step-by-step explanation:
A
let the cost of notebook be n, cost of pen be p
1. 4n + 3p = 14.5
2. 5n + 6p = 21.5
by 1, you can get 3p = 14.5 - 4n, put it into 2
5n + 2(14.5 - 4n) = 21.5
5n + 29 - 8n = 21.5
3n = 29 - 21.5 = 7.5
n = 2.5
put n = 2.5 into 1
4(2.5) + 3p = 14.5
3p = 4.5
p = 1.5
B
Waseem buy 3 notebooks for each pen, let number of pen be m, then the number of notebook will be 3m
m(2.5) + 3m(1.5) < 27
2.5m + 4.5m = 7m < 27
m < 27/7
maximum integer value for m = 3
