For the following hypothesis test, H0: μ ≥ 150Ha: μ < 150the test statistic a. must be positive. b. must be negative. c. can be either negative or positive. d. must be a number between zero and one.

(1)      

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".  

And since we are conducting a lower unilateral lest  then we expected that the value for the statistic would be negative. And the correct answer would be:

b. must be negative

Step-by-step explanation:

Data given and notation      

represent the sample mean    

represent the standard deviation for the sample      

sample size      

represent the value that we want to test    

represent the significance level for the hypothesis test.    

t would represent the statistic (variable of interest)      

represent the p value for the test (variable of interest)  

State the null and alternative hypotheses.      

We need to conduct a hypothesis in order to determine if the mean is lower than 150, the system of hypothesis would be:      

Null hypothesis:      

Alternative hypothesis:      

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:      

(1)      

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".  

And since we are conducting a lower unilateral lest  then we expected that the value for the statistic would be negative. And the correct answer would be:

b. must be negative

50 min

step-by-step explanation:

they will be decreasing both their times in half

60 / 2 = 30

40/2 = 20

30 + 20 = 50

positive

step-by-step explanation:

the quadrant is facing upwards