z-score
After an exam, you learn that the mean for the class is 60, with a standard deviation of 10. Suppose your exam score is 70. What is your Z-score?
z = +1
What is the probability of an event that will NEVER occur?
0 or 0%
In recent years, it was found that teenagers between ages 13 - 17 send/receive an average of 1740 text messages per month with a standard deviation of 550 text messages.
What is the z-score for a teenager who sends/receives 2150 text messages per month?
0.745
What are the numbers used in the Emperical Rule?
68 - 95 - 99.7
Who was recently awarded Music Artist of the Decade at the Music Awards?
Taylor Swift
What is the z-score for a runner, with an average run of about 08:00:00 (H:M:S) and the data collected was N(00:09:00, 00:00:30)?
The runners z-score would be z = -2
What is the probability of an event that is CERTAIN to occur?
1 or 100%
In recent years, it was found that teenagers between ages 13 - 17 send/receive an average of 1740 text messages per month with a standard deviation of 550 text messages.
If a teenager has a z-score of 1.38, about how many text messages did he or she send/receive that month?
2499
What rule is used to determine if a value is an outlier or not? Show the use of the formula.
1.5 x IQR
Then look at Q1 - (1.5xIQR) for lower bound and Q3 + (1.5 x IQR) for upper bound.
What is the name of the song AND artist that includes the following line:
I'm gonna ride 'til I can't no more
Old Town Road by Lil Nas.
Watermelons have been picked from the farm and recorded on a normal distribution, with a standard deviation of 2 ounces. What is the mean if 85% of the cucumbers weigh less than 16 ounces?
Using Appendix A, we get a z-score of 1.04. The manipulating our z formula, we get the mean to be 16 - (1.04)(2) = 13.92
How many sides are on a coin?
2
The Virginia Cooperative Extension reports that the mean weight of yearling (1-yo) Angus cattle is 1150 lbs. with a standard deviation of 80 lbs.
What is the z-score for a cow weighing 980 lbs.?
-2.125
On a standardized test with a normal distribution, the mean is 88. If the standard deviation is 4, the percentage of grades that would be expected to lie between 80 and 96?
Approximately 95%
What are the names of the four main characters in Frozen?
Anna
Elsa
Olaf
Kristoff
Say a person scores a 725 on a math SAT on a set of data with (N(500, 100). What is that person’s percentile?
The person is approximately at the 99th percentile.
What is the probability of rolling an even number with one standard die?
3/6 = 1/2
The Virginia Cooperative Extension reports that the mean weight of yearling (1-yo) Angus cattle is 1150 lbs. with a standard deviation of 80 lbs.
Is a cow weighing 1340 unusual? Explain.
Yes. The z-score is more than 2 s.d. from the mean.
If the mean on a standardized test with a normal distribution is 54.3 and the standard deviation is 4.6, what is the best approximation of the percent of the scores that fall between 54.3 and 63.5?
Approximately 47.5%
When is the next official leap year AND can one tell for sure?
The year 2020.
It can be evenly divided by four.
Which is the better score for a student, who scored 590 on an SAT and a 35 on the ACT?
Given, that the mean SAT score is 550 and the mean score for the ACT is 16. While the standard deviation for SAT is 75 and the Standard deviation for ACT is 7.
The ACT, which has a higher z-score of 2.71, compared to the SAT z-score of 0.53.
What is the probability of pulling out a red card with the face of a King?
2/52 = 1/26
x = (z)(s.d.) + mean
Consider the contingency table provided by your host. What is the probability that a randomly chosen Technology student is female?
5/50 or 1/10 or 10%
Which team won the NBA Title for 2018 and which team did they beat?
Golden State Warriors and they beat the Cleveland Cavaliers. (Swept them in four games)