Answer:
Step-by-step explanation:
You don't need the Law of Cosines, the Law of sines if what you need. You can't use the Law of Cosines because in order to find side a, you would need the length of side c and you don't have it. Using the Law of Sines is appropriate, knowing that angle B = 55:
and solving for a:
so
a = 143.0
Answer: (110.22, 125.78)
Step-by-step explanation:
The confidence interval for the population mean is given by :-
Given : Sample size = 463
Significance level :
Critical value :
We assume that the population is normally distributed.
Now, the 90% confidence interval for the population mean will be :-
Hence, 99% confidence interval for the mean study time of all first-year students = (110.22, 125.78)
Answer:
mFG = 67r ( Where r is the radius of the circle)
∠ECF = 67°
Step-by-step explanation:
i) m FG
Join CG
∠GCF=67°
(As FG=ED and equal chords subtend equal angle at center)
Now The length of the minor arc is given by the formula
m arc FG =
∠C=67
m arc FG =
m arc FG = 67r
Where r is the radius of the circle.
2. ∠ECF = 67°
It is because of the rule which says that equal chords subtend equal angle at center
DE = EF
Hence ∠DCE = ∠ECF