1. The average person in the United States has a typing net speed of 40 words pe
ID: 3219350 • Letter: 1
Question
1. The average person in the United States has a typing net speed of 40 words per minute (WPM). Findout your net typing speed by going to:http://www.typingtest.com/test/default.aspA random sample of students at the University of Maryland was sampled to determine their net typing –see below. Use this information to test whether or not students at the University of Maryland have asignificantly different average net speed than people in the United States. 7 pts
Class Mean: 48.9 wpm/ Class Standard Deviation: 6.2 / Class size: 28
a) State the question (ID the population)
b) State your null and alternative hypotheses (define symbols)
c) Analyze your data statistically.
d) Assume the 1 tail critical value is 1.7. 2 tail critical value = 2.05 Do you reject or not reject the nullhypothesis
e) Provide a statement of conclusion that includes the statistical evidence and makes inference back to the population.
2. For each of the following, determine whether the question is left, right or both tailed
questions. 2 pts each
a) You want to know if your improved hair growth formula results in different length of hair thanthe known growth rate of hair which is 1 cm per month. You have a sample of size 30.
Is this a left, right, both tailed question?
b) Do University of Maryland students do better at solving rubic’s cubes compared to the USpopulation average of 13 minutes? You have a sample of 24 students
Is this a left, right, both tailed question?
c) You lead 40 students through a study guide for the next biometrics test. Do these students dosignificantly better than the class average of 122 points?
Is this a left, right, both tailed question?
3. You TA will send around a slip of paper for you to record your personal data anonymously.Check yes if you HAVE been to the dentist in the last 6 months, check no if you have NOT beento the dentist in the last 6 months. Use your discussion section’s sample percentage that havebeen to the dentist in the last months as a sample for the entire Biom301 Spring 2014 class totest whether Biom301 are significantly less likely to go to the dentist compared to the USaverage of 55%. Your TA will put your sample data on the board. 7 pts.Class data: p' = n=
a) State the question (ID the population)
b) State your null and alternative hypotheses (define symbols)
c) Analyze your data statistically. Assume the one tailed test has a critical value of 1.65 and a two tailedtest has a critical value of 1.96.
d) Provide a statement of conclusion that includes the statistical evidence and makes inference back to the population
Explanation / Answer
1. (a) Here the population denotes the typing speed of entire population of US and from that we have extract the sample of University of Maryland to check whether the typing speed in aforesaid university is same or not.
(b) Null Hypothesis : H0: Average Net typing speed at University of Maryland is equal to 40 words per minute. (typemaryland = 40)
Alternative Hypothesis : Ha : Average Net typing speed at University of Maryland is not equal to 40 words per minute. [ type maryland 40]
(c) Class Mean: 48.9 wpm/ Class Standard Deviation: 6.2 / Class size: 28
Test statistic t = (class mean - population mean) / ( std dev/ sqrt(n))
= (48.9 - 40)/ (6.2/sqrt(28) = 8.9/ 1.7117 = 5.20
2 tail critical value = 2.05
(d) and we can see that t < t(critical) so we can reject the null hypothesis and can say that typing speed of students in University of Maryland is not same as population of US, which is 40 wpm.
Q.2 (a) Two - tailed as we are checking difference
(b) Right - tailed as problem includes word "better".
(c) Right - tailed as it include word "better".
Q>3
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.