here you go. Thank you for your kindness :) The National Highway Traffic Safety
ID: 3133052 • Letter: H
Question
here you go.
Thank you for your kindness :)
The National Highway Traffic Safety Administration found the average U.S. EMS response time from EMS notification to arrival at the crash scene in urban areas to be 6.85 minutes. A random sample of 20 reported fatal crashes in South Dakota had a mean notification-to-arrival time of 5.25 minutes with a sample standard deviation of 2.78 minutes. Assuming that response times follow a Normal distribution, use a 5% level of significance to test the claim that population mean response times are lower in South Dakota than the national average...Explanation / Answer
1.
a)
Formulating the null and alternative hypotheses,
Ho: u >= 6.85
Ha: u < 6.85 [ANSWER]
As we can see, this is a left tailed test.
********************
b) We will use a one-sample t test. We have a normally distributed population, and we have a small sample with unknown population standard deviation, so we use a one-sample t test.
**********************
c)
Getting the test statistic, as
X = sample mean = 5.25
uo = hypothesized mean = 6.85
n = sample size = 20
s = standard deviation = 2.78
Thus, t = (X - uo) * sqrt(n) / s = -2.573891197
df = n - 1 = 19
Hence, the p value is, as this is left tailed,
p = 0.009295579 [ANSWER, P VALUE]
************************
d)
As P < 0.05, we REJECT HO. [ANSWER]
***********************
e)
There is significant evidence at 0.05 level that the mean response times are lower in South Dakota than the national average. [CONCLUSION]
*******************************************
Hi! Please submit the next part as a separate question. That way we can continue helping you! Please indicate which parts are not yet solved when you submit. Thanks!
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.