Question

Rory suspects that teachers in his school district have less than 5 yearſ of experience on average. He

Answer 1

Answer:

Teachers in his school district have less than 5 yearſ of experience on average is true.

Step-by-step explanation:

Sample mean = $\bar{x}=4$

Sample standard deviation = s = 2

We are supposed to to test Ha :u= 5 versus H : u < 5 using a sample of 25 teachers

$H_a:\mu=5\\H_0:\mu < 5$

n = 25

Since n<30 and population standard deviation is unknown

So, we will use t test

Formula : $t=\frac{x-\mu}{\frac{s}{\sqrt{n}}}$

$t=\frac{4-5}{\frac{2}{\sqrt{25}}}$

t=-2.5

$\alpha = 0.05$

Degree of freedom = n-1 = 25-1 = 24

Refer the t table

$t_{df,\frac{\alpha}{2}}=t_{24,\frac{0.05}{2}}=2.064$

t critical > t calculated

So, We are failed to reject null hypothesis

So,  teachers in his school district have less than 5 yearſ of experience on average is true.