According to the census bureau, 3.13 people reside in the typical american household. a sample of 25 households in arizona retirement communities showed the mean number of residents per household was 2.86 residents. the standard deviation of this sample was 1.20 residents. the null hypothesis that should be used for deciding whether the mean number of residents in the arizona retirement communities is significantly less than the 3.13 is:

μ=3.13 (the mean number of residents in the Arizona retirement communities is 3.13)

Step-by-step explanation:

Alternative hypothesis would be:

μ<3.13

Then z-score of the sample of 25 households in Arizona retirement communities with mean number 2.86 residents per household  and the standard deviation of 1.20 residents is calculated under the assumptions of null hypothesis and checked against the critical value of a given significance level.

answer: yes youre right.

step-by-step explanation:

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m