Answer:
0.6 = 60% probability that it is either sunny or rainy.
Step-by-step explanation:
We solve this question treating these events as Venn probabilities.
I am going to say that:
Event A: Rain
Event B: Sun
The chance of rain is 20%
This means that 
The chance of it being sunny is 60%
This means that 
The chance of it being sunny and rainy at the same time is 10%.
This means that 
Calculate, the probability that it is either sunny or rainy.
This is:

0.6 = 60% probability that it is either sunny or rainy.
Orders are a, b, c, lets write equations to represent the problem's info:
a + b = 150
b + c = 100
a + c = 150
so we have 3 unknowns and 3 equations, so we can solve.
<span>Use the first equation:
a + b = 150
</span>a = 150 - b
and substitute in the 3rd:
<span>a + c = 150
</span>150 - b + c = 150
then
b = c
and we can substitute that in the original equation:
<span>b + c = 100
</span>2b = 100
b = 50
c = 50
and substitute in the first equation:
<span>a + b = 150
</span>a = 150 - b = 150 - 50
a = 100
then a = 100, b = c = 50
Answer:

Step-by-step explanation:
We are given the following in the question:
Sample size, n = 67
Variance = 3.85
We have to find 80% confidence interval for the population variance of the weights.
Degree of freedom = 67 - 1 = 66
Level of significance = 0.2
Chi square critical value for lower tail =

Chi square critical value for upper tail =

80% confidence interval:

Putting values, we get,

Thus, (3.13,4.91) is the required 80% confidence interval for the population variance of the weights.
Answer:
Lower Bound = 2.996
Upper bound = 3.244
Step-by-step explanation:
6n - 13 = 27
6n = 27 + 13
6n = 40
n = 40/6
n = 6 2/3
Answer: n = 6 2/3