Summary
Summary STK110-TUTORIAL 10
- Course
- STK 110 (STK110)
- Institution
- University Of Pretoria (UP)
with these past papers you are guaranteed a distinction with lots of practice!!!!!!!!!
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
Content preview
STK110 Preparation sheet: TUT 10 memo 2023Question 1
A researcher would like to investigate whether females start smoking cigarettes at an older age than males.
A total of 20 females and 15 males are selected randomly from normal populations and the descriptive
statistics for the age of the respondents are tabulated below. Use 𝛼 0.01
Females (Population 1) Males (Population 2)
Sample size (𝑛 ) 20 15
Sample mean (𝑥̅ ) 20 18
Population variance (𝜎 ) 5.6 4.5
Let: 𝜇 population mean of the age of the females
𝜇 population mean of the age of the males
a. Formulate the hypotheses.
𝐻 :𝜇 𝜇 0
𝐻 :𝜇 𝜇 0
b. Determine the rejection rule using the 𝑝 value approach.
Reject 𝐻 if 𝑝 0.01
c. Calculate the value of the test statistic and the 𝑝 value.
𝑥̅ 𝑥̅ 𝐷 20 18 0
𝑧 2.6261 2.63
𝜎 5.6 4.5
𝜎
20 15
𝑛 𝑛
𝑝 value: 𝑝 𝑃 𝑧 2.63 1 𝑃 𝑧 2.63 1 0.9957 0.0043
d. Make a decision.
0.0043 0.01, Reject 𝐻 at a 0.01 level of significance.
e. Conclude and interpret.
At a 0.01 level of significance there is sufficient evidence to conclude that the mean age of females to
start smoking cigarettes is significantly older than men.
Question 2
A researcher wants to test whether there is a difference between the mean nicotine absorption from e-
cigarettes and tobacco cigarettes. He has drawn two independent random samples from populations that
are normally distributed and used a significance level of 𝛼 0.05.
The nicotine absorption (ng/ml) from e-cigarettes and tobacco cigarettes are noted and the following statistics
calculated:
e-cigarettes (Population 1) tobacco cigarettes (Population 2)
𝑛 = 10 𝑛 = 12
𝑥̅ = 9.6 𝑥̅ = 15.6
𝑠 =9 𝑠 = 14
Given: The degrees of freedom = 18
Let: 𝜇 population mean nicotine absorption from e-cigarettes
𝜇 population mean nicotine absorption from tobacco cigarettes
a. Calculate the point estimate of 𝜇 𝜇 .
1
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller thembisilemagudulela. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R70,00. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
82191 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now