8-A bakery stated that the average number of breads sold daily is 3000. An employee thinks that the actual
value might differ from this and wants to test this statement. The correct hypotheses are:
(1) H0 : ¦Ì = 3000 H1 : ¦Ì not= 3000
(2) H0 : ¦Ì > 3000 H1 : ¦Ì ¡Ü 3000
(3) H0 : ¦Ì = 3000 H1 : ¦Ì = 3000
(4) H0 : ¦Ì > 3000 H1 : ¦Ì not= 3000
(5) H0 : ¦Ì ¡Ü 3000 H1 : ¦Ì > 3000
ANSWER: 1
9-A statistics practitioner formulated the following hypothesis: H0 : ¦Ì = 200 against H1 : ¦Ì < 200 and
learned that x = 190 n = 9 and ¦Ò = 50.
The p¨C value of the test is
(1) 0.6
(2) 0.2743
(3) 0.7743
(4) −0.2743
(5) Cannot be found with information given
ANSWER: 5 (we need the level of significance)
10-In a sample of 500 college students fifty percent of all college students attend schools within 50 miles of
their homes.
The probability that the population proportion will be between 0.45 and 0.55 is
(1) 0.4875
(2) 0.9818
(3) 0.4909
(4) 0.9750
(5) 0.5000
answer: 4
11-Suppose the mass of college students can be modeled by the normal distribution. We believe the mean
of the normal distribution is 72 kg. We randomly sample 18 students and find an average of 69 kg and a
standard deviation of 4kg.
A. The standard error of ¦Òx is 0.9428
B. A t-statistic can be calculated and it is equal to −3.18
C. The degrees of freedom for the t-distribution will be 17
The correct statement(s) is(are)
(1) Only A
(2) All three statements are correct.
(3) B and C
(4) A and B
(5) A and C
ANSWER: 5
I don't know if your symbol stands for the mean. You can use μ, if you can copy and paste this symbol. Otherwise, it might be better to print out "mean."
8. Correct
9. I don't know what you mean by the "p¨C value."
11. Correct
To answer these questions, we need to understand some statistical concepts and hypothesis testing. Let's go through each question and explain the concepts involved:
8- This is a hypothesis testing question, where we want to test the statement made by the bakery. The null hypothesis (H0) is a statement of no effect or no difference, while the alternative hypothesis (H1) is the statement we want to support. Among the given options, the correct hypotheses are (1) H0: µ = 3000 and H1: µ ≠ 3000, which indicates that the average number of breads sold daily may differ from 3000.
9- In this question, we are given the null hypothesis H0: µ = 200 and the alternative hypothesis H1: µ < 200. We also have the sample mean x = 190, the sample size n = 9, and the standard deviation σ = 50. However, to calculate the p-value of the test, we need the level of significance. Without that information, we cannot determine the p-value. The correct answer is (5) Cannot be found with the information given.
10- This question involves the probability of the population proportion being between two values. We are told that in a sample of 500 college students, 50% of them attend schools within 50 miles of their homes. The probability that the population proportion will be between 0.45 and 0.55 can be calculated using the normal distribution. The correct answer is (4) 0.9750.
11- This question is about sample mean and standard deviation. We have a sample of 18 students and their average mass is 69 kg, with a standard deviation of 4 kg. The correct statements are: A. The standard error of σx is 0.9428, B. A t-statistic can be calculated and it is equal to -3.18, and C. The degrees of freedom for the t-distribution will be 17. The correct answer is (5) A and C.
Note: It's important to have a deeper understanding of these statistical concepts to solve similar questions correctly.