Answer:
The t value for 99% CI for 21 df is 2.831.
The critical value that should be used in constructing the confidence interval is (64.593, 86.407).
Step-by-step explanation:
Now the sample size is less than 30 and also population standard deviation is not known.
Then we will use t distribution to find CI
t value for 99% CI for 21 df is TINV(0.01,21)=2.831
The margin of error is
Hence CI is
Answer: 4in
Step-by-step explanation:
Volume of a cylinder = πR²H
Volume of a cone = 1/3πr²h
πR²H = 1/3πr²h
π is very common so it could be cancelled, so the equation now becomes
R²H = 1/3r²h
3R²H = r²h
Now substitute for the values
h = 3 x 2² x 3
--------------
3²
= 9 x 4/9
= 4in.
Therefore, the height of the cone
h = 4in.
Answer:
Distance between A and B is 2672 km.
Step-by-step explanation:
Since one city B is having latitude of 23° and other town is having latitude of 47°.Radius of Earth has been given as 6380 km.
Therefore arc A from x-axis will be A = 2πr(∅/360) = 2×3.14×6380×(47/360)
= 5230.90 km
Now arc B from x-axis = 2πr(∅'/360) = 2×3.14×6380(23/360) = 2559.80 km
Therefore distance between them = 5230.9-2559.8 = 2671.9 ≅ 2672 km
Now we will rewrite the arc length formula in radians.
arc A = r×(∅×π/180)
arc A = 6380×(47×π/180) = 1665.9π
arc B = 6380×(23×π/180) = 815.22π
Now the distance between A and B = 850.68π
If the 5 scores have a mean of 8, then their total sum would be 8*5 = 40
Now if one score if added (let's call this score x), there are 6 scores and the mean changes to 9, thus:
(40 + x)/6 = 9
40 + x = 54
x = 14
Answer:
I guess Sofia is doing better than the other three students