Aresearcher conducts a hypothesis test on a population proportion. her null and alternative hypothesis are h0 : p = 0.4 and ha : p < 0.4 . the test statistic and p-value for the test are z = −3.01 and p−value = 0.0013 . for a significance level of α = 0.05 , choose the correct conclusion regarding the null hypothesis.

The null hypothesis is not true for these values

Step-by-step explanation: The null hypothesis as described by the established p-values correspond to non-significant variables, that is, p = 0.4 (higher than the significance level). Since the result is p-value = 0.0013, the results reveal that there is statistical significance p-value <0.4, and therefore, the alternative hypothesis is true.

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.