Answer :
Answer:
The decision rule is
Reject the null hypothesis
The conclusion is
There is sufficient evidence to conclude that the mean size of California homes exceeds the national average
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 2390 \ ft^2[/tex]
The sample size is n = 100
The sample mean is [tex]\= x = 2 507 \ ft^2[/tex]
The standard deviation is [tex]s = 257 \ ft^2[/tex]
The level of significance is [tex]\alpha = 0.01[/tex]
The null hypothesis is [tex]H_o : \mu = 2390[/tex]
The alternative hypothesis is [tex]H_a : \mu > 2390[/tex]
Generally the test statistics is mathematically represented as
[tex]z = \frac{ \= x - \mu }{ \frac{s}{ \sqrt{n} } }[/tex]
=> [tex]z = \frac{2507 - 2390 }{ \frac{ 257 }{ \sqrt{100 } } }[/tex]
=> [tex]z = 4.55[/tex]
From the z table the area under the normal curve to the left corresponding to 4.55 is
[tex]p-value = P( X > 4.55 ) = 0.00[/tex]
From the value obtained we see that [tex]p-value < \alpha[/tex] hence
The decision rule is
Reject the null hypothesis
The conclusion is
There is sufficient evidence to conclude that the mean size of California homes exceeds the national average