Answer:
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 25 - 1 = 24
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.064
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 81.5 - 4.21 = 77.29
The upper end of the interval is the sample mean added to M. So it is 81.5 + 4.21 = 85.71.
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Answer:
Step-by-step explanation:
a). Since, ΔABC ~ ΔWYZ
Their corresponding sides will be proportional.
--------(1)
By applying Pythagoras theorem in ΔABC,
AB² = AC² + BC²
BC² = AB² - AC²
BC² = (194)² - (130)²
BC² = 20736
BC = 144
From equation (1)
WY = 
WY = 
= 1.35
WZ = 
WZ = 
= 0.90
b). tan(A) = 
= 
= 
Since, ΔABC ~ ΔWYZ,
∠A ≅ ∠W
Therefore, tangent of angle A and angle W will measure .
Answer:
c= 0 m=6
Step-by-step explanation:
0x2= 0
3x6=18
18+0=18$
It is C (2, 1) I think it is because they intersect
Answer:
Okay well first we right down what we already know:
- volume of 2,355 cubic inches
- the height is 10 inches
Now we write down the equation for the volume of a cone:
V = πr²
lets plug in what we know into the equation
2,355 = πr²
now we simplify to solve for r
2,355 / 10/3 = 706.5 = πr²
706.5/π = r²= 224.89
now since its r² we take the square root of 224.89
r = 15 inches
for diameter we multiply 15 by 2
diameter = 30 inches
