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:
See the IMAGE FOR SOLUTION
Brainlost please
Answer:
Country A = 85, Country B = 29, Country C = 20
Step-by-step explanation:
A+B+C=134 ----- eq(1)
B=C+9 ------------ eq(2)
A=36+B+C ------ eq(3)
By substituting eq(2) in eq(3), we get:
A=36+C+9+C
A=2C+45 ------- eq(4)
Now substituting eq(2) & eq(4) in eq(1), we get
2C+45+C+9+C=134
4C+54=134
4C=134-54
4C=80
C=20
Now putting the value of C in eq(2),
B=20+9
B=29
Substituting the value of B & C in eq(1), we get:
A+29+20=134
A+49=134
A=134-49
A=85
I'm not sure if you need the answer or just the steps to start, so I will just give u the steps. First, just take a step back and take it one step at a time. Once you have an idea of how the two triangles are congruent, make 2 columns, one with statements and one with reasons. On the statements side, put given information and what you learn along the way, like if it is given x=y, and y=z, then what you can put down after that is x=z. On the reasons side, put the properties or formulas you used to reach your solution. For instance, if x=y and y=z, x=z by the Transitive property of equality. Proofs are time consuming, tedious and utterly frustrating. Just take it slowly and you will be fine.