The sales of a grocery store had an average of $7,000 per day. The store introduced several advertising campaigns in order to increase sales. To determine whether or not the advertising campaigns have been effective in increasing sales, a sample of 100 days of sales was selected. It was found that the average was $7,280 per day. From past information, it is known that the standard deviation of the population is $1,000. The null hypothesis for this problem is

Null hypothesis: ∪ = $7,000

Step-by-step explanation:

The null hypothesis is a general statement that there is no relationship between two measured instances or no association among groups.

In this case, the sales of a grocery store had an average of $7,000 per day is the null hypothesis. Then the research was carried out to test for the effectiveness of the advertising campaigns in increasing sales.

Thus, this is the alternative hypothesis. The researchers wish to test against the null with regards to the involvement of the advertising campaigns.

Thus, the null hypothesis is just the average sales without the advertising campaigns which is

Null hypothesis: ∪ = $7,000

Alternative hypothesis: ∪ ≠ $7,000

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)