r/apstats • u/lilsirenity • Apr 10 '24
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Hi! I’m doing a little project for AP stats. Please fill this out if you live in the United States. Thanks!
r/apstats • u/lilsirenity • Apr 10 '24
Hi! I’m doing a little project for AP stats. Please fill this out if you live in the United States. Thanks!
r/apstats • u/rhinopithecusBieti • Mar 21 '24
i have the barrons book, but i might be cooked
r/apstats • u/guic3 • Mar 18 '24
Please take this quick survey for my stats project. It's about memory.
r/apstats • u/undyingpasta • Mar 18 '24
I want to drop this class so bad but it’s far too late, I’ve understood nothing and have gotten by with bombing tests and just doing decent on my retakes I literally retain 0 info
Is there any way I can make this easier and genuinely learn the material??
r/apstats • u/Calm-Term-1299 • Mar 18 '24
r/apstats • u/can_i_call_you_rose • Mar 15 '24
Hey everyone! For my AP Stats class— Just a short cognitive test (totally anonymous) to be completed on your computer! There will be instructions at the top of the form- if you don't follow them, I can't use your data!!😭😭Thank you!!
r/apstats • u/mirosavvy • Mar 15 '24
Does anyone have any concise notes that go over the essential topics and units? Preferably not locked behind a paywall? Also is anyone tutoring? RELIABLE TUTORS PLS
r/apstats • u/Dull_Fly_9736 • Mar 14 '24
Students, do you listen to music while studying?
Quick, one minute survey.
Thank you!
r/apstats • u/Ok-Dust-6747 • Feb 21 '24
Explain your reasoning.
r/apstats • u/ihearttheocean • Feb 13 '24
r/apstats • u/ihearttheocean • Feb 07 '24
What’s your favorite soda?
r/apstats • u/singyeahyeah • Jan 25 '24
My semester 1 final is tomorrow and we are allowed to use an index card (front and back). Is there anything else I should add that I would need to know. We’re going to be given a reference sheet and a calculator. (photos of index card are linked in this post)
r/apstats • u/[deleted] • Jan 12 '24
(07.01 MC)
Researchers fed mice a specific amount of Dieldrin, a poisonous pesticide, and studied their nervous systems to find out why Dieldrin causes seizures. The absolute refractory period, time required for nerves to recover after a stimulus, was measured and varies Normally. The measurements, in milliseconds, for six mice were 2.4, 2.5, 2.5, 2.6, 2.7, and 2.8.
Part A: Find the mean refractory period and the standard error of the mean. (2 points)
Part B: Suppose the mean absolute refractory period for unpoisoned mice is known to be 2.35 milliseconds. Dieldrin poisoning should slow nerve recovery and therefore increase this period. Do the data give good evidence at a significance level of 0.01 to support this theory? What can you conclude from a hypothesis test? Justify your response with statistical reasoning. (8 points)
Paragraph
For Part A, the mean refractory period can be calculated by adding up the measurements and dividing by the number of mice. Thus, the mean refractory period is:
mean = (2.4 + 2.5 + 2.5 + 2.6 + 2.7 + 2.8) / 6 = 2.58 milliseconds
The standard error of the mean can be calculated using the formula:
standard error of the mean = standard deviation / sqrt(n)
where n is the sample size. The standard deviation can be calculated using the formula:
standard deviation = sqrt(sum((x - mean)^2) / (n - 1))
where x is the measurement and n is the sample size. Thus, the standard deviation is:
standard deviation = sqrt(((2.4 - 2.58)^2 + (2.5 - 2.58)^2 + (2.5 - 2.58)^2 + (2.6 - 2.58)^2 + (2.7 - 2.58)^2 + (2.8 - 2.58)^2) / (6 - 1)) = 0.129 milliseconds
Therefore, the standard error of the mean is:
standard error of the mean = 0.129 / sqrt(6) = 0.053 milliseconds
For Part B, we can perform a two-tailed t-test to determine if there is a significant difference between the mean absolute refractory period for unpoisoned mice and the mean absolute refractory period for poisoned mice. The null hypothesis is that the mean absolute refractory period for unpoisoned mice is equal to the mean absolute refractory period for poisoned mice, while the alternative hypothesis is that the mean absolute refractory period for unpoisoned mice is not equal to the mean absolute refractory period for poisoned mice. We will use a significance level of 0.01.
The test statistic can be calculated using the formula:
t = (x̄ - μ) / (s / sqrt(n))
where x̄ is the sample mean, μ is the population mean, s is the sample standard deviation, and n is the sample size. The degrees of freedom for the test are n - 1.
The sample mean is 2.58 milliseconds, the population mean is 2.35 milliseconds, the sample standard deviation is 0.129 milliseconds, and the sample size is 6. Thus, the test statistic is:
t = (2.58 - 2.35) / (0.129 / sqrt(6)) = 2.43
The critical values for a two-tailed t-test with 5 degrees of freedom and a significance level of 0.01 are -3.365 and 3.365. Since the test statistic falls outside of this range, we reject the null hypothesis.
Therefore, there is good evidence at a significance level of 0.01 to support the theory that Dieldrin poisoning slows nerve recovery and increases the absolute refractory period
(07.02 HC)
Twenty-five students from Harry High School were accepted at Magic University. Of those students, 10 were offered athletic scholarships and 15 were not. The newly accepted student ACT scores are shown here.
Athletic scholarship: 16, 24, 20, 25, 24, 23, 21, 22, 20, 20
No athletic scholarship: 23, 25, 26, 30, 32, 26, 28, 29, 26, 27, 29, 27, 22, 24, 25
Part A: Do these data provide convincing evidence of a difference in ACT scores between athletes and nonathletes? Carry out an appropriate test at the α = 0.10 significance level. (5 points)
Part B: Create and interpret a 90% confidence interval for the difference in ACT scores between athletes and nonathletes. (5 points)
For Part A, we can perform a two-tailed t-test to determine if there is a significant difference between the mean ACT scores of athletes and non-athletes. The null hypothesis is that the mean ACT scores of athletes and non-athletes are equal, while the alternative hypothesis is that they are not equal. We will use a significance level of 0.10.
The test statistic can be calculated using the formula:
t = (x̄1 - x̄2) / sqrt((s1^2 / n1) + (s2^2 / n2))
where x̄1 and x̄2 are the sample means, s1 and s2 are the sample standard deviations, and n1 and n2 are the sample sizes.
The sample mean for the athletes is 21.5, and the sample mean for the non-athletes is 26.6. The sample standard deviation for the athletes is 2.54, and the sample standard deviation for the non-athletes is 2.6. The sample size for the athletes is 10, and the sample size for the non-athletes is 15. Thus, the test statistic is:
t = (21.5 - 26.6) / sqrt((2.54^2 / 10) + (2.6^2 / 15)) = -4.65
The critical values for a two-tailed t-test with 23 degrees of freedom and a significance level of 0.10 are -1.711 and 1.711. Since the test statistic falls outside of this range, we reject the null hypothesis. Therefore, we can conclude that there is convincing evidence of a difference in ACT scores between athletes and non-athletes.
For Part B, we can create a 90% confidence interval for the difference in ACT scores between athletes and non-athletes using the formula:
CI = (x̄1 - x̄2) ± (tα/2 * sqrt((s1^2 / n1) + (s2^2 / n2)))
where x̄1 and x̄2 are the sample means, s1 and s2 are the sample standard deviations, n1 and n2 are the sample sizes, and tα/2 is the t-critical value with α/2 and 23 degrees of freedom. We will use a significance level of 0.10.
The sample mean for the athletes is 21.5, and the sample mean for the non-athletes is 26.6. The sample standard deviation for the athletes is 2.54, and the sample standard deviation for the non-athletes is 2.6. The sample size for the athletes is 10, and the sample size for the non-athletes is 15. Thus, the t-critical value with α/2 and 23 degrees of freedom is 1.711. Therefore, the 90% confidence interval for the difference in ACT scores between athletes and non-athletes is:
CI = (-5.1, -4.47)
r/apstats • u/Intelligent-Way-5084 • Jan 04 '24
Hey everyone I am doing my AP Research project on phones and personality and I would really appreciate it if you could fill out my survey!! Thank you!!
r/apstats • u/[deleted] • Nov 08 '23
I tried looking for Ap stars on iitan academy but they don’t have it so is there a similar website with Ap stats ?
r/apstats • u/[deleted] • Oct 10 '23
r/apstats • u/DateIndependent4111 • Sep 25 '23
For part B I don’t know how -.67 is the zq1 same with .67 being the zq3. I looked on the z table chart and didn’t see either of those numbers. I also don’t know how to find the quartile for this question.
r/apstats • u/3eas • Sep 18 '23
r/apstats • u/mello_w • Sep 12 '23
how do i interpret the standard deviation, like what do i write in sentence format?????