Answer:
Yes, there is sufficient evidence to support the claim that the mean cost is $1.
Step-by-step explanation:
Data Given:
The population standard deviation [tex]\sigma[/tex] = $0.2
The sample mean cost [tex]\bar {X}[/tex] = $0.93
The sample size n = 12
From above we can use the Z-test for testing the mean from the above given data.
To check whether the mean cost of newspaper is $1.00
[tex]\mathbf{H_o}[/tex] : [tex]\mu[/tex] = $1
[tex]\mathbf{H_1}[/tex] : [tex]\mu[/tex] [tex]\neq[/tex] $1
The test statistics Z = [tex]\frac{\bar {X}- \mu}{\frac{\sigma }{\sqrt{n}} }[/tex]
Z = [tex]\frac{0.93- 1}{\frac{0.2}{\sqrt{12}} }[/tex]
Z = -1.212
The P-value = 2P (Z< - 1.212)
= 2 × 0.1128
= 0.2256
Since the value of P is more than the significance level; do not reject the [tex]\mathbf{H_o}[/tex]
Conclusion: We therefore conclude that there is sufficient evidence to support the claim that the mean cost is $1.
