Answer:
5
Step-by-step explanation:
The interquartile range is the difference between the upper quartile and the lower quartile.
First find the median.
The median is the middle value of the data set arranged in ascending order
1 5 5 7 9 ← data in ascending order
↑ median
The lower quartile is the middle value of the data to the left of the median. If there is not an exact middle then it the average of the values on either side of the middle.
1 5
↑ lower quartile = 
= 3
The upper quartile is the middle value of the data to the right of the median.
7 9
↑ upper quartile = 
= 8
Thus
interquartile range = 8 - 3 = 5
The answer to #1 is 9 to 30
the answer to #2 is 4 to 3
Answer:
B, C, D, & E
Step-by-step explanation:
All lines intersect the x axis and y axis so we know B and D are correct. All graphs are in the xy plane unless i (
) is involved, or C. It crosses the center (origin) of the entire plane so it crosses the origin, or E.
Answer:
(45.6965,63.2035)
Step-by-step explanation:
Given that in an examination of holiday spending (known to be normally distributed) of a sample of 16 holiday shoppers at a local mall, an average of $54 was spent per hour of shopping.
i.e. 
Margin of error = t critical * std error=9.2035
df = 15
(Here since sample std dev is known we use t critical value)
Confidence interval lower bound = 
Upper bound = 
