Answer:
a) Mean = 84.14
b) Median = 85
c) Mode = no mode (since there is no variable that appears more than once in this dataset)
d) Midrange = 84
e) Range = 12
f) Variance = 14.69
g) Standard deviation = 3.83
Step-by-step explanation:
The raw data to be processed is
87 85 80 78 83 86 90
a) Mean = (Σx)/N
The mean is the sum of variables divided by the number of variables
x = each variable
N = number of variables = 7
Mean = (87+85+80+78+83+86+90)/7
Mean = 84.14
b) Median is the number in the middle of the dataset when the variables are arranged in ascending or descending order.
Arranging the data in ascending order
78, 80, 83, 85, 86, 87, 90
The number in the middle is the 4th number = 85
Median = 85
c) Mode is the variable that occurs the most in a distribution.
For this question, all of the variables occur only once, with no variable occurring more than once. Hence, there is no mode for this dataset.
d) Midrange is the arithmetic mean of the highest and lowest number in the dataset.
Mathematically,
Midrange = (Highest + Lowest)/2
Midrange = (90 + 78)/2
Midrange = 84
e) Range is the difference the highest and the lowest numbers in a dataset.
Range = 90 - 78 = 12
f) Variance is an average of the squared deviations from the mean.
Mathematically,
Variance = [Σ(x - xbar)²/N]
xbar = mean
Σ(x - xbar)² = (78 - 84.14)² + (80 - 84.14)² + (83 - 84.14)² + (85 - 84.14)² + (86 - 84.14)² + (87 - 84.14)² + (90 - 84.14)² = 102.8572
Variance = (102.8572)/7
Variance = 14.69
g) Standard deviation = √(variance)
Standard deviation = √(14.69)
Standard deviation = 3.83
Hope this Helps!!!