Question

---Find the 98% confidence interval for the difference between two means based on this information about two samples. Assume independent samples from normal populations. (Use conservative degrees of freedom.) (Give your answers correct to two decimal places.)

Sample	Number	Mean	Std. Dev.
1	18	40	30
2	17	28	25

Lower Limit
Upper Limit

---Find the value of t for the difference between two means based on an assumption of normality and this information about two samples. (Use sample 1 - sample 2. Give your answer correct to two decimal places.)

Sample	Number	Mean	Std. Dev.
1	28	37.2	15
2	23	42.3	10.9

---If a random sample of 20 homes south of a town has a mean selling price of $145,375 and a standard deviation of $4825, and a random sample of 23 homes north of a town has a mean selling price of $148,550 and a standard deviation of $5925, can you conclude that there is a significant difference between the selling price of homes in these two areas of the town at the 0.05 level? Assume normality.

(a) Find t. (Round your answer to two decimal places.)


(ii) Find the p-value. (Round your answer to four decimal places.)

---Twenty laboratory mice were randomly divided into two groups of 10. Each group was fed according to a prescribed diet. At the end of 3 weeks, the weight gained by each animal was recorded. Do the data in the following table justify the conclusion that the mean weight gained on diet B was greater than the mean weight gained on diet A, at the α = 0.05 level of significance? Assume normality. (Use Diet B - Diet A.)

Diet A	14	5	7	12	12	10	8	6	9	10
Diet B	20	23	15	22	13	19	17	19	23	8

(a) Find t. (Give your answer correct to two decimal places.)


(ii) Find the p-value. (Give your answer correct to four decimal places.)

Answer 1