I assume you mean, that an angle and two sides are known.
A formula that can be used for irregular triangles is the cosine rule.

'b' and 'c' must be sides that are beside the angle 'A' (angle opposite 'a').
Answer:
-41
Step-by-step explanation:
The change is -2
(-2*20)-1 = -41
Answer:
The best recommendation is to: Increase the sample size.
Step-by-step explanation:
The width of a confidence interval
,depends on three things,
- Sample size (n)
- Standard deviation
- Confidence level
To decrease the width the following options can be used:
- Increase the sample size.
Since the sample is inversely proportional to the width of the confidence interval, increasing the value of <em>n</em> will decrease the width.
- Decrease the standard deviation.
The standard deviation is directly proportional to the width of the confidence interval. On decreasing the standard deviation value the width of the interval will also decrease.
- Decrease the confidence level.
The critical value of the distribution is based on the confidence level. Higher the confidence level, higher will be critical value.
So, on deceasing the confidence level the critical value will decrease, hence decreasing the width of the interval.
Thus, the best recommendation is to: Increase the sample size.
Answer: Mean = 52.8 mins
Step-by-step explanation:
We have lapses of 30 minutes, so we can write the average for each, this means that:
0 < t < 30 can be averaged to the middle of the range: 15 min.
Doing this, we have that:
7 students 15 min
27 students 45 min
12 students 75 min
4 students 105 min.
Now we can calculate the mean:
mean = (x1*n1 + x2*n2 + ...)/N
where x1 is the amount of time 1, and n1 is the number of students associated to that time and so on. N is the total number of students
Mean = (7*15min + 27*45min + 12*75min + 4*105min)/(7 + 27 + 12 + 4)
Mean = 52.8 mins