Whether we are conducting a hypothesis test with regards to a one population parameter or two population parameters (usually the difference between two population parameters), the concept of p-value is extremely important in making a decision with respect to the null hypothesis. A very common mistake in elementary statistics is interpreting the p-value of a hypothesis test. Many students think that the p-value is the probability that the null hypothesis is true or that it is the probability of rejecting the null hypothesis:
In: Statistics and Probability
The national average on a reading test is 72. The average for a sample of 80 students in a certain geographical region who took the exam is 70. If the population standard deviation is 12, then test the claim that the average test score for students in this region statistically different from the national average. Let LaTeX: \alphaα =5% .
State the claim: LaTeX: H_0\:\:\:\muH 0 μ ______ 72
LaTeX: H_1\:\muH 1 μ LaTeX: \ne≠72 claim
Determine the direction of the tails: Left, Right, or Two:
Find the critical value: +/-
Compute Test Point (round to 2 place values) :
Do we Reject or Do Not Reject?
Summarize: There is enough evidence to _______________ the claim.
In: Statistics and Probability
Scores on the SAT critical reading test in 2015 follow a Normal distribution with a mean of 495 and a standard deviation of 116
a. What proportion of students who took the SAT critical reading test had scores above 600?
b. What proportion of students who took the SAT critical reading test had scores between 400 and 600?
c. Jacob took the SAT critical reading test in 2015 and scored a 640. Janet took the ACT critical reading test which also follows a Normal distribution with a mean of 21 and a standard deviation of 5.5. Janet scored a 31 on the ACT critical reading test. Who did better?
In: Statistics and Probability
Students are asked to rate their preference for one of four video games. The following table lists the observed preferences in a sample of 100 students. State whether to retain or reject the null hypothesis for a chi-square goodness-of-fit test given the following expected frequencies. (Assume alpha equal to 0.05.)
| Video Games | ||||
|---|---|---|---|---|
| McStats |
Tic-Tac Stats |
Silly Stats |
Super Stats |
|
|
Frequency observed |
25 | 25 | 25 | 25 |
(a) expected frequencies: 70%, 10%, 10%, 10%, respectively
Retain the null hypothesis.Reject the null hypothesis.
(b) expected frequencies: 25%, 25%, 25%, 25%, respectively
Retain the null hypothesis.Reject the null hypothesis.
In: Statistics and Probability
Suppose a college student at a university presents to a physician with symptoms of headaches, fever, and joint pain. Let A = {headaches, fever, and joint pain}, and suppose that the possible disease state of the patient can be partitioned into: B1 = normal, B2 = common cold, B3 = mumps. From clinical experience, the physician estimates P (AjBi ): P (AjB1) = 0.001, P (AjB2) = 0.70, P (AjB3) = 0.95. The physician, aware that some students have contracted the mumps, then estimates that for students at this university, P (B1) = 0.95, P (B2) = 0.025, and P (B3) = 0.025.
Given the previous symptoms, which of the disease states is most likely? Be sure to clearly show your work.
In: Statistics and Probability
The Graduate Management Admission Test (GMAT) has scores from 100 to 900.
Scores are supposed to follow a Normal distribution with a mean of 500 and standard deviation of 150.
a. Suppose you earned a 800 on your GMAT test. From that information and the 68-95-99.7 Rule, where do you stand among all students who took the GMAT?
b.Suppose you earned a 450 on your GMAT test. Where do you stand among all students who took the GMAT?
c. Assuming the GMAT scores are nearly normal with N(500, 150), what proportion of GMAT scores falls between 400 and 700?
In: Statistics and Probability
Cultured liver hepatocytes are convenient for studying both exocytosis and receptor-mediated, clathrin-dependent endocytosis. As part of an advanced laboratory in cell biology, students are required to perform mutation studies on cultured liver hepatocytes to generate data that supports the proposed mechanism of receptor-mediated, clathrin-dependent endocytosis. Liver hepatocytes are cultured, mutagenized, and screened for defective receptor-mediated endocytosis. In order to distinguish unique mutants from one another, the students must design a series of experiments to distinguish between mutants that have the following mutations:
a). Cellular adaptor proteins are mutated to be non-functional
b). Clathrin is mutated to be non-functional
c). Dynamin is mutated to be non-functional
In: Biology
You are to test if the average SAT score in the high school students of Ontario is greater than 495. You set the hypotheses as below:
H0: µ = 495 vs Ha: µ > 495
If the SRS of 500 students were selected and the standard deviation has been known to 100, with alpha = 0.05, answer the followings.
a. What is the Type I error?
b. What is the Type II error if the true population mean is 510. Explain it.
c. What is the power if the true population mean is 510? Explain it.
Please show your work and thank you SO much in advance! You are helping a struggling stats student SO much!
In: Statistics and Probability
A non-profit program for youths sends students to summer camp. The price of the program is $800 per student, and there are 8 students that can participate in each program. Each program runs for 11 days. The price for all food and equipment is $100 per student per day. Also, the two program guides cost $150 a day to hire.
a. What is the profit margin for the program?
b.The non-profit was able to get a grant to cover $200 per student per day. Will this be enough to cover the full cost of the program?
c. Given the cost of the program, if the non-profit secured the grant, would you recommend they continue to operate the program based on the economics?
In: Finance
1. A sports scientist collects strength data from two groups of students. The first group is a group of athletes who might be expected to be strong, and the second group is a control group of nonathletic students. The first group has strength ratings of: c(129.4, 111.8, 127.7, 130, 120.7, 118.2, 121.9) And the second group has strength ratings of: c(149.1, 111.6, 122.1, 126.4, 123.3, 105.5, 127.3, 101.2, 113.3 ) Is there evidence that the first group is actually stronger than the second?
(a) State a sensible null hypothesis
(b) Is a one-sided or two-sided test needed? justify
(c) Perform a student t-test using R and interpret
In: Statistics and Probability