You are in charge of selling advertising for radio station WQAA.
The fee you can set for airtime is directly related to the share of the listening market your station reaches.
From time to time, you conduct surveys to determine WQAA’s share of the market.
This month, when you contacted 200 randomly selected residential phone numbers, 12 respondents said they listen to WQAA.
How large a sample size will need to be selected if we wish to be 99% confident of being within 2% of the actual population percentage of the market who are WQAA listeners?
Holding goods in inventory is costly because inventoried goods are susceptible to breakage and other forms of physical damage.
Typically, the amount of damage increases with the level of inventory, but some of the damage is unrelated to the amount of inventory.
In addition, the seasonality may make a difference.
A random sample of 10 observations is selected with the variables INVTRY (X1, inventory in $1,000,000s), SEASON (X2, with spring and summer being 0 and fall and winter being 1), and DAMAGE (Y, in $10,000s).
The results are found below.
INVTRY SEASON DAMAGE
11 1 80
15 1 100
13 0 70
10 1 60
7 0 50
9 0 70
13 1 100
10 0 65
14 1 95
8 0 54
15 0 96
9 1 91
13 1 85
Perform the multiple regression t-tests on, (use two tailed test with (? = .
Interpret your results.
Predict the damage for a single case in the spring or summer with an inventory of $12,000,000.
Use both a point estimate and the appropriate interval estimate.