STT100 Statistics for Business - Assignment

Running head: STT100 STATISTICS FOR BUSINESS
STT100 STATISTICS FOR BUSINESS
Name of the Student
Name of the University
Author Note

STT100 STATISTICS FOR BUSINESS1
Step 1:
The list of countries by median age data is obtained from the link.
https://en.wikipedia.org/wiki/List_of_countries_by_median_age
Now, the median years column is copied from the excel sheet and pasted to the online
statistical tool. The online statistical tool outputs the mean and standard deviation of median
ages of all the countries. The output is shown below.
Hence, from the online descriptive statistics calculator it is found that mean of the data is
approximately 30.74( μ0 ¿ and standard deviation is 8.89(σ).
Now, the country which is selected has much higher median (in years) than the computed
average or mean of 30.74. The selected country is Andorra and has the median (in years) of
44.3.
Step 2:

STT100 STATISTICS FOR BUSINESS2
Now, hypothesis testing is performed to check whether the median age of Andorra is
significantly different from the average.
Null hypothesis (H0): The median age of Andorra is same as the average of median ages of
all countries ( x = μ0).
Alternative Hypothesis (H1): The median age of Andorra is significantly different from the
average of median ages of all countries ( x ≠ μ0).
The level of significance for the hypothesis testing is considered to be 5% or 0.05.
Now, as the standard deviation of the population i.e. the median ages of all countries is
known, hence, z test is applied here.
The sample size is the total number of countries in the world which are listed in excel file.
Sample size n = 230.
Now, from the ‘≠’ sign in alternative hypothesis the test is a two tailed test. Now, from
standard normal table the z score corresponding to 5% significance or 1- 0.05 = 95%
confidence level is 1.96 (Barrett 2017).
Hence, critical value is zcrit = 1.96.
Now, the test statistic of z test is given by,
z =
x−μ0
σ
√ n
=
30.74 – 44.3
8.89
√ 230
= 30.74 – 44.3
0.586 =¿-23.14
Step 3: