Answer:
26.11% of the test scores during the past year exceeded 83.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by
After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
It is known that for all tests administered last year, the distribution of scores was approximately normal with mean 78 and standard deviation 7.8. This means that 
.
Approximately what percentatge of the test scores during the past year exceeded 83?
This is 1 subtracted by the pvalue of Z when 
. So:
has a pvalue of 0.7389.
This means that 1-0.7389 = 0.2611 = 26.11% of the test scores during the past year exceeded 83.
Circumference is equal to two times pi times radius
C=2π(7)
43.96 in
If there were just one question, then the probability of guessing correctly would be 1/3.
Since all the answers are independent (the answer to one question has no bearing on the answers to the others), then this is the case with each question, so the chances of guessing all answers correctly is 1/3 × 1/3 × 1/3 = 1/27. Independent choices are linked by multiplication.
To have exactly 2 answers correct, we have to think of which one is wrong: there are 3 questions and any single one could be wrong. The probability that the first question is wrong is 2/3. And we know that the probabilities of the other two being right is 1/3 each, so the probability of just the first question being wrong and the others right is 2/3 × 1/3 × 1/3 = 2/27. But this is just one of the three cases: 1/3 × 2/3 × 1/3 and 1/3 × 1/3 × 2/3 also both equal 2/27 each. So here we add the cases together: 2/27 + 2/27 + 2/27 = 6/27 = 2/9. So the answer to part (a) of your question is 2/9.
To solve (b) Consider that (b) is the same as (a) with "all answers right" added in. So you can simply add answer (a) to the chance of guessing all answers correctly.
To solve (c) it might help you to think of the equivalent problem: what is the probability of getting 0 correct plus the probability of getting 1 correct?
Answer:
Q6: B Q7: D Q8: C Q9: D Q10: A
Answer:
Step-by-step explanation:
<u>Step 1: Determine the equation</u>
So we know that our equation does not have a y-intercept which means that it doesn't intersect ANYWHERE on the y-axis. Therefore, this means that our equation will be a straight vertical line that doesn't move side to side and just goes straight up and down. We also know that our point is (3, 6) which means that our x-value will be 3 and this is where the equation will be located.
There are several ways to display our answer where x = 3 is the most common way which basically means give me all of the y-values for the same x value of 3. Another way of saying it is x - 3 = 0 which either way when adding 3 to both sides gives you x = 3 which is what I usually go with.
Answer:
