Lisa is currently taking physics as one of her electives in school. her grade at the end of the year is determined by the averag
1 answer:
The score which Lisa should get in her fourth exam of school to get exactly 80% in the course is 64.
<h3>What is the average of a group of numbers?</h3>The average of the group of numbers is the ratio of the sum of all the numbers of the group to the total number of the group.
Lisa is currently taking physics as one of her electives in school.
Her grade at the end of the year is determined by the average of four exams, each worth 100 points.
- On her first test, she got an 84,
- On her second, she got a 92,
- On her third, an 80.
She got exactly 80% in the course. Let she scores x marks in her fourth exam. Thus,
Hence, the score which Lisa should get in her fourth exam of school to get exactly 80% in the course is 64.
Learn more about the average here;
You might be interested in
Answer:
b) No, it's not independent.
c) 0.02
d) 0.59
e) 0.57
f) 0.5616
Step-by-step explanation:
To answer this problem, a Venn diagram should be useful. The diagram with the information of Event 1 and Event 2 is shown below (I already added the information for the intersection but we're going to see how to get that information in the b) part of the problem)
Let's call A the event that she passes the first course, then P(A)=.73
Let's call B the event that she passes the second course, then P(B)=.66
Then P(A∪B) is the probability that she passes the first or the second course (at least one of them) is the given probability. P(A∪B)=.98
b) Is the event she passes one course independent of the event that she passes the other course?
Two events are independent when P(A∩B) = P(A) * P(B)
So far, we don't know P(A∩B), but we do know that for all events, the next formula is true:
P(A∪B) = P(A) + P(B) - P(A∩B)
We are going to solve for P (A∩B)
.98 = .73 + .66 - P(A∩B)
P(A∩B) =.73 + .66 - .98
P(A∩B) = .41
Now we will see if the formula for independent events is true
P(A∩B) = P(A) x P(B)
.41 = .73 x .66
.41 ≠.4818
Therefore, these two events are not independent.
c) The probability she does not pass either course, is 1 - the probability that she passes either one of the courses (P(A∪B) = .98)
1 - P(A∪B) = 1 - .98 = .02
d) The probability she doesn't pass both courses is 1 - the probability that she passes both of the courses P(A∩B)
1 - P(A∩B) = 1 -.41 = .59
e) The probability she passes exactly one course would be the probability that she passes either course minus the probability that she passes both courses.
P(A∪B) - P(A∩B) = .98 - .41 = .57
f) Given that she passes the first course, the probability she passes the second would be a conditional probability P(B|A)
P(B|A) = P(A∩B) / P(A)
P(B|A) = .41 / .73 = .5616
Comment
The measurement of an arc in degrees is the same as the central angle. We must assume that the central angle is the measurement given.
= 49
To find the next one you need to find the measurement from B to C, the arc that is over 180 degrees. Maybe you could put another letter between B and C so that we could refer to that top arc greater than 180 degrees. Call the point you inserted D.
= 360 - 49 - 107 = 204
= +
Arc(ABC) = 204 + 49 = 253
Arc(BAC) = Arc(BC) + Arc(AB)
Arc(BAC) = 107 + 49
Arc(BAC) = 156
Arc(ACB) = 107 + 204 = 311
The measurement of an arc in degrees is the same as the central angle. We must assume that the central angle is the measurement given.
To find the next one you need to find the measurement from B to C, the arc that is over 180 degrees. Maybe you could put another letter between B and C so that we could refer to that top arc greater than 180 degrees. Call the point you inserted D.
Arc(ABC) = 204 + 49 = 253
Arc(BAC) = Arc(BC) + Arc(AB)
Arc(BAC) = 107 + 49
Arc(BAC) = 156
Arc(ACB) = 107 + 204 = 311
If you meant "
" instead of "
"
Then,
is rounded 
& 
is rounded to 
Your answer:
Then,
Your answer: