Answer:
At the 5% level, BAOI can infer that the average time to complete does not exceeds 60 hours.
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 60 \ hr[/tex]
The sample size is [tex]n = 16[/tex]
The sample mean is [tex]\= x = 68 \ hr[/tex]
The standard deviation is [tex]\sigma = 20 \ hr[/tex]
The null hypothesis is [tex]H_o : \mu = 60[/tex]
The alternative [tex]H_a : \mu > 60[/tex]
Here we would assume the level of significance of this test to be
[tex]\alpha = 5\% = 0.05[/tex]
Next we will obtain the critical value of the level of significance from the normal distribution table, the value is [tex]Z_{0.05} = 1.645[/tex]
Generally the test statistics is mathematically represented as
[tex]t = \frac{ \= x - \mu}{ \frac{ \sigma }{\sqrt{n} } }[/tex]
substituting values
[tex]t = \frac{ 68 - 60 }{ \frac{ 20 }{\sqrt{16} } }[/tex]
[tex]t = 1.6[/tex]
Looking at the value of t and [tex]Z_{\alpha }[/tex] we see that [tex]t< Z_{\alpha }[/tex] hence we fail to reject the null hypothesis
This means that there no sufficient evidence to conclude that it takes more than 60 hours to complete the course
So
At the 5% level, BAOI can infer that the average time to complete does not exceeds 60 hours.
