How do u do (number 30)... please list step by step...
1 answer:
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Answer:
The data item is
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation
, the z-score of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. 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 p-value, we get the probability that the value of the measure is greater than X.
Mean of 400 and a standard deviation of 60.
This means that
z=3
We have to find X when Z = 3. So
The data item is
Answer:
D had 310 points.
The final ranking is: B,A,D,C
Step-by-step explanation:
The problems states that:
There are 115 votes.
Each ballot has a vote for first place, that counts 4 points, a vote for second place, that counts 3 points, a vote for third place, that counts 2 points and a vote for fourth place that counts 1 point. This means that each ballot has 4+3+2+1 = 10 points.
Since there are 115 voters, there are 115 ballots. This means that the total points of A,B,C and D combined must be equal to 115*10 = 1150. So:
We already know that:
A had 320 points, B had 330 points, and C had 190 points.
So:
B had the most points, followed by A, D and C. So the final ranking is: B,A,D,C