HELPPPPPPPPP ASAPPPPPPPPPPPPPPPPPPPPPP!
2 answers:
You might be interested in
Answer:
The top 20% of the students will score at least 2.1 points above the mean.
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean and standard deviation
, the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
The mean of a certain test is 14 and the standard deviation is 2.5.
This means that
The top 20% of the students will score how many points above the mean
Their score is the 100 - 20 = 80th percentile, which is X when Z has a pvalue of 0.8. So X when Z = 0.84.
Their score is:
16.1 - 14 = 2.1
The top 20% of the students will score at least 2.1 points above the mean.
We have been given that a graph that represents the amount of money in dollars that Tony expects to deposit in his account in terms of the number of years since opening the account.
We are asked to find the rate of change and initial value from our given graph.
We know that initial value is the point, where, graph intersects y-axis that is when x is equal to 0.
We can see that graph starts at 5000 on y-axis, therefore, initial value is $5000.
The rate of change will be equal to slope of line. Let us find slope of line using points (0,5000) and (1,7500).
Therefore, the rate of change is $2500 per year.
The equation represents the amount of money in dollars that Tony expects to deposit in his account.