Answer:
yes, all answers are correct
Step-by-step explanation:
Answer:
Step-by-step explanation:
The formula for determining the confidence interval for the difference of two population means is expressed as
Confidence interval = (x1 - x2) ± z√(s²/n1 + s2²/n2)
Where
x1 = mean sale amount for mail order sales = 82.70
x2 = mean sale amount for internet sales = 66.9
s1 = sample standard deviation for mail order sales = 16.25
s2 = sample standard deviation for internet sales = 20.25
n1 = number of mail order sales = 17
n2 = number of internet sales = 10
For a 99% confidence interval, we would determine the z score from the t distribution table because the number of samples are small
Degree of freedom =
(n1 - 1) + (n2 - 1) = (17 - 1) + (10 - 1) = 25
z = 2.787
Margin of error =
z√(s²/n1 + s2²/n2) = 2.787√(16.25²/17 + 20.25²/10) = 20.956190
Answer:b
Step-by-step explanation:
Answer:
58.1 cm
Step-by-step explanation:
The length of each support rod can be found using the Pythagorean theorem. The geometry can be modeled by a right triangle, such that the distance from centre is one leg and half the length of the rod is the other leg of a triangle with hypotenuse equal to the radius of the grill.
__
<h3>Pythagorean theorem</h3>
The theorem tells us that the sum of the squares of the legs of a right triangle is the square of the hypotenuse. For legs a, b and hypotenuse c, this is ...
c² = a² +b²
<h3>application</h3>
For the geometry of the grill, we can define a=7.5 and c=30. Then b will be half the length of the support rod.
30² = 7.5 +b²
b² = 900 -56.25 = 843.75
b = √843.75 ≈ 29.0473
The length of each support rod is twice this value, so ...
rod length = 2b = 2(29.0473) = 58.0947
Each support rod is about 58.1 cm long.
Sub g to (-3) and then solve from there using PMDAS and equation solving skills, Photomath is a fantastic resource