The weights of four randomly and independently selected bags of tomatoes labeled 5.0 pounds were found to be 5.1​, 5.0​, 5.4​, and 5.5 pounds. Assume Normality. Answer parts​ (a) and​ (b) below. a. Find a​ 95% confidence interval for the mean weight of all bags of tomatoes. (nothing comma nothing )​(Type integers or decimals rounded to the nearest hundredth as needed. Use ascending​ order.) b. Does the interval capture 5.0 ​pounds? Is there enough evidence to reject a mean weight of 5.0 ​pounds? A. The interval does not capture 5.0 ​pounds, so there is enough evidence to reject a mean weight of 5.0 pounds. It is not plausible the population mean weight is 5.0 pounds. B. The interval captures 5.0 ​pounds, so there is enough evidence to reject a mean weight of 5.0 pounds. It is not plausible the population mean weight is 5.0 pounds. C. The interval does not capture 5.0 ​pounds, so there not is enough evidence to reject a mean weight of 5.0 pounds. It is plausible the population mean weight is 5.0 pounds. D. The interval captures 5.0 ​pounds, so there is not enough evidence to reject a mean weight of 5.0 pounds. It is plausible the population mean weight is 5.0 pounds.

Respuesta :

Answer:

(a) 95% confidence interval for the mean weight of all bags of tomatoes is [4.87 pounds , 5.63 pounds].

(b) The interval captures 5.0 ​pounds, so there is not enough evidence to reject a mean weight of 5.0 pounds. It is plausible the population mean weight is 5.0 pounds.

Step-by-step explanation:

We are given that the weights of four randomly and independently selected bags of tomatoes labeled 5.0 pounds were found to be 5.1​, 5.0​, 5.4​, and 5.5 pounds.

Firstly, the pivotal quantity for 95% confidence interval for the population mean is given by;

                          P.Q. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex]  ~ [tex]t_n_-_1[/tex]

where, [tex]\bar X[/tex] = sample mean weight of bags of tomatoes = [tex]\frac{\sum X}{n}[/tex] = 5.25 pounds

             s = sample standard deviation = [tex]\sqrt{\frac{\sum (X-\bar X)^{2} }{n-1} }[/tex] = 0.24 pounds

             n = sample of bags = 4

             [tex]\mu[/tex] = population mean weight of all bags of tomatoes

Here for constructing 95% confidence interval we have used One-sample t test statistics as we know don't about population standard deviation.

So, 95% confidence interval for the population mean weight, [tex]\mu[/tex] is ;

P(-3.182 < [tex]t_3[/tex] < 3.182) = 0.95  {As the critical value of t at 3 degree of

                                        freedom are -3.182 & 3.182 with P = 2.5%}  

P(-3.182 < [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] < 3.182) = 0.95

P( [tex]-3.182 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]{\bar X-\mu}[/tex] < [tex]3.182 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95

P( [tex]\bar X-3.182 \times {\frac{s}{\sqrt{n} } }[/tex] < [tex]\mu[/tex] < [tex]\bar X+3.182 \times {\frac{s}{\sqrt{n} } }[/tex] ) = 0.95

95% confidence interval for [tex]\mu[/tex] = [ [tex]\bar X-3.182 \times {\frac{s}{\sqrt{n} } }[/tex] , [tex]\bar X+3.182 \times {\frac{s}{\sqrt{n} } }[/tex] ]

                  = [ [tex]5.25-3.182 \times {\frac{0.24}{\sqrt{4} } }[/tex] , [tex]5.25+3.182 \times {\frac{0.24}{\sqrt{4} } }[/tex] ]

                  = [4.87 pounds , 5.63 pounds]

(a) Therefore, 95% confidence interval for the mean weight of all bags of tomatoes is [4.87 pounds , 5.63 pounds].

(b) Yes, the above confidence capture 5.0 pounds as it will lie within the two value of 4.87 pounds and 5.63 pounds.

Since, the interval captures 5.0 ​pounds, so there is not enough evidence to reject a mean weight of 5.0 pounds. It is plausible the population mean weight is 5.0 pounds.