Which of the following statements are correct? I. The t distribution has more ar

Question

Which of the following statements are correct?

I. The t distribution has more area in its tails than the z distribution for all n

II. When constructing a 2-sample t interval for the difference of means the conservative method of choosing degrees of freedom will result in a wider confidence interval than other methods.

III. You would always use a z procedure rather than a t procedure if you have a sample size greater than 30.

An experiment was conducted to compare the efficacies of two drugs in the prevention of tapeworms in the stomachs of a new breed of sheep. Samples of size 5 and 8 from each breed were given the drug and the two sample means were 28.6 and 40.0 worms/sheep. The variances in the two groups are 198 and 232, respectively, and that the number of worms in the stomachs has an approximate normal distribution. A 95% confidence interval for the the difference in the mean number of worms per sheep is:

1.

Which of the following statements are correct?

I. The t distribution has more area in its tails than the z distribution for all n

II. When constructing a 2-sample t interval for the difference of means the conservative method of choosing degrees of freedom will result in a wider confidence interval than other methods.

III. You would always use a z procedure rather than a t procedure if you have a sample size greater than 30.

II only II and III only I and II only I, II, and III I and III only

Explanation / Answer

1.
I and III only

2.
-11.4

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.