Answer:
1
The correct option is b
2
The correct option is h
Step-by-step explanation:
From the question we are told that
The sample size is n = 15
The difference in population proportion is [tex]d = 6[/tex]
Generally the sample mean of the input temperature is
[tex]\= x_1 = \frac{\sum x_i }{n}[/tex]
=> [tex]\= x_1 = \frac{57.6 + 68.9 + \cdots +60.4 }{15}[/tex]
=> [tex]\= x_1 = 62.57 [/tex]
Generally the sample mean of the output temperature is
[tex]\= x_2 = \frac{\sum x_i }{n}[/tex]
=> [tex]\= x_2 = \frac{65.1 + 74.4 + \cdots +67.3 }{15}[/tex]
=> [tex]\= x_2 = 55.97 [/tex]
Generally the difference of the sample mean of the input temperature and that of the output temperature is
[tex]\= d = \= x_1 - \= x_2[/tex]
=> [tex]\= d = 62.57 -55.97[/tex]
=> [tex]\= d = 6.6[/tex]
Generally the standard deviation is mathematically represented as
[tex]s_d = \sqrt{\frac{\sum(d_1 - \= d )^2}{n} }[/tex]
=> [tex]s_d = \sqrt{\frac{([57.6- 65.1]- 6.6)^2+ ([68.9 - 74.4]- 6.6)^2 + \cdots + ([60.4 - 67.3]- 6.6)^2 }{15} }[/tex]
=> [tex]s_d = 1.732 [/tex
Generally the test statistics is mathematically represented as
[tex]t = \frac{ d - \= d }{ \frac{s_d}{\sqrt{n} } }[/tex]
=> [tex]t = \frac{ 6-6.6 }{ \frac{1.732}{\sqrt{15} } }[/tex]
=> [tex]t = 1.3417[/tex]
Generally the degree of freedom is mathematically represented as
[tex]df = n - 1[/tex]
=> [tex]df = 15 - 1[/tex]
=> [tex]df = 14[/tex]
Generally the probability of t obtained from the t - distribution table at a degree of freedom of [tex]df = 14[/tex] is
[tex]P(t >1.3417 ) = 0.10052569[/tex]
Generally the p-value is mathematically represented as
[tex]p-value = 2 * P(t > 1.3417)[/tex]
=> [tex]p-value = 2 * 0.10052569[/tex]
=> [tex]p-value = 0.201 [/tex]
From the values obtained we see that [tex]p-value > \alpha[/tex] hence
The decision rule is
Fail to reject the null hypothesis
The conclusion is
The cooling system changes the temperature of the water by 6 degrees.
