Well he earned $50 this week and $25 the following week, so 2/5 of $75 is $30
Answer: The probability that both televisions work is 0.5625 .
The probability at least one of the two televisions does not work is 0.4375.
Step-by-step explanation:
Given : Number of televisions received in shipment= 12
Number of defective televisions received in shipment= 3
Then proportion of defective televisions =
Using binomial probability formula, the probability of getting success in x trials is given by :-
If two televisions are randomly selected, then the probability that both televisions work will be :-
The probability at least one of the two televisions does not work will be :-
Answer:
The probability is 0.9211
Step-by-step explanation:
Let's call K the event that the student know the answer, G the event that the student guess the answer and C the event that the answer is correct.
So, the probability P(K/C) that a student knows the answer to a question, given that she answered it correctly is:
P(K/C)=P(K∩C)/P(C)
Where P(C) = P(K∩C) + P(G∩C)
Then, the probability P(K∩C) that the student know the answer and it is correct is:
P(K∩C) = 0.7
On the other hand, the probability P(G∩C) that the student guess the answer and it is correct is:
P(G∩C) = 0.3*0.2 = 0.06
Because, 0.3 is the probability that the student guess the answer and 0.2 is the probability that the answer is correct given that the student guess the answer.
Therefore, The probability P(C) that the answer is correct is:
P(C) = 0.7 + 0.06 = 0.76
Finally, P(K/C) is:
P(K/C) = 0.7/0.76 = 0.9211
The first and crucial thing we want to take notice is that the lines DF and EG intersect at point H which creates 4 different triangles in the rhombus. The innermost angles of DGH and EFH are vertical angles and vertical angles are congruent. So if the angles of the triangles are congruent than the triangles themselves are congruent. This is supported by the vertical angles theorem.
Answer:
a) The formula is given by mean 
the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
b) 
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
If the distribution for X is normal or if the sample size is large enough we know that the distribution for the sample mean 
is given by:
Part a
The formula is given by mean the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
Part b
The confidence interval for the mean is given by the following formula:
