(20 PTS!!)
2 answers:
Answer:
The correct option is C.
Step-by-step explanation:
In a dot plot, the number of dots above a number represents the frequency of that number.
From the given dot plot it is clear that number of dots for group R is 21 and the time taken by the students of groups R are
45, 50, 50, 55, 60, 60, 70, 75, 80, 85, 90, 90, 95, 100, 100, 105, 110, 110, 115, 120, 120
The average of the data is
From the given dot plot it is clear that number of dots for group S is 17 and the time taken by the students of groups S are
50, 55, 60, 60, 65, 70, 70, 80, 90, 90, 95, 100, 105, 110, 110, 115, 120
The average time of both groups are same.
Since both groups show about the same average time, therefore the correct option is C.
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Answer:
If this is the sample data, the sample variance is 125.07 and the sample standard deviation is 11.18
If this is a population data, the population variance is 109.44 and the population standard deviation is 10.46
Step-by-step explanation:
We are given the following data-set:
70, 65, 71, 78, 89, 68, 50, 75
Deviations from the mean
–0.75, –5.75 , 0.25, 7.25, 18.25, –2.75, –20.75, 4.2
Sample size, n = 8
Sample:
where are data points,
is the mean and n is the number of observations.
Sum of squares of differences =
0.5625 + 33.0625 + 0.0625 + 52.5625 + 333.0625 + 7.5625 + 430.5625 + 18.0625 = 875.5
Population:
where are data points,
is the mean and n is the number of observations.
Sum of squares of differences =
0.5625 + 33.0625 + 0.0625 + 52.5625 + 333.0625 + 7.5625 + 430.5625 + 18.0625 = 875.5