A sample of 25 undergraduates reported the following dollar amounts of entertainment expenses last year:
1 answer:
Answer:
A.
mean = 724.2
Median = 715
Mode = 768
B.
Range = 85
Standard deviation = 29.30
C.
Interval = [665.6, 782.8]
Step-by-step explanation:
Number of samples n = 25
Summation X= 769 + 691 + 699 +730+711+ 765+ 702 718 +719 +712+ 768 +688 +757+695 768 +735 +709 +758 +708+ 693 +736 700+ 687 +772 +715 = 18105
A.
1. Mean = 18105/25
= 724.2
2. Median is the middle value when arranged from the least value to the highest = 715
3. Mode is the number with the highest frequency = 768 (occured two times)
B.
1. Range = highest value - lowest value
Highest value = 772
Lowest value = 687
772-687 = 85
2. Standard deviation = √(X-barX)²/n-1
= √20604/25-1
=√858.5
= 29.30
Please check attachment for the full calculation of the standard deviation
C.
Interval
[Mean - 2(sd), mean + 2(sd)]
= [724.2-2x29.3, 724.2+2x29.3]
=[665.6, 782.8]
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