Answer
Mean: 6
Mode: None
Median: 6
First Moment: 6
Second Moment: 40
Variance: 4
Assumed Mean (using 7): 6
Solution
We are given the sevenβvalue data set
ββ4,β7,β5,β9,β8,β3,β6
and asked to find several βmomentsβ and measures. (Note that the spellings are nonβstandard, e.g. βmoteβ means mode, βfuostmenentβ means first moment (about the origin), βonginβ is taken to be the central moment (variance), and βArsumed, mean of 7β means the estimated mean using 7 as an assumed value.)
Letβs work through each part.
βββββββββββββββββββββββββββββ
Step 1. Preliminary Calculations
a. It is often helpful to know the sample size and sum.
ββ’ Number of data, n = 7.
ββ’ Sum of the data = 4 + 7 + 5 + 9 + 8 + 3 + 6 = 42.
βββββββββββββββββββββββββββββ
(i) The Mean
The mean is the sum divided by the number of observations.
βMean = 42β7 = 6
βββββββββββββββββββββββββββββ
(ii) The Mote (Mode)
The mode is the value(s) that occur most frequently. Here, every number appears exactly once. Thus, there is no unique mode (or you may say βno modeβ).
βMode = None
βββββββββββββββββββββββββββββ
(iii) The Median
The median is the middle number when the data are arranged in order. First, sort the data:
ββ3, 4, 5, 6, 7, 8, 9
Since there are 7 values, the median is the 4th one.
βMedian = 6
βββββββββββββββββββββββββββββ
(iv) The Fuostmenent (First Moment about the Origin)
The βfirst moment about the originβ is essentially the mean. In other words, it is
βFirst moment = (1/n) Γ (sum of data) = 42/7 = 6
βββββββββββββββββββββββββββββ
(v) Second Moment
The βsecond moment about the originβ is the average of the squares of the data. We calculate each square then average them.
βCalculate squares:
ββ4Β² = 16,β7Β² = 49,β5Β² = 25,β9Β² = 81,β8Β² = 64,β3Β² = 9,β6Β² = 36
βSum of squares = 16 + 49 + 25 + 81 + 64 + 9 + 36 = 280
βSecond moment = 280β7 = 40
βββββββββββββββββββββββββββββ
(vi) The Ongin
The wording βthe onginβ is not standard, but in this context it is reasonable to interpret it as the central moment (the second central moment), which is the variance. (Remember that
βVariance = (1/n) Γ [Ξ£(x β mean)Β²].)
We already have the mean = 6, so find the squared deviations:
βFor x = 4:β(4 β 6)Β² = 4
βFor x = 7:β(7 β 6)Β² = 1
βFor x = 5:β(5 β 6)Β² = 1
βFor x = 9:β(9 β 6)Β² = 9
βFor x = 8:β(8 β 6)Β² = 4
βFor x = 3:β(3 β 6)Β² = 9
βFor x = 6:β(6 β 6)Β² = 0
βSum of squared deviations = 4 + 1 + 1 + 9 + 4 + 9 + 0 = 28
βVariance = 28β7 = 4
So, the βonginβ (central second moment) = 4
βββββββββββββββββββββββββββββ
(vii) Arsumed, Mean of 7 (Assumed Mean Method)
Here we use an assumed value, A = 7. The idea is to write each observation as
βx = A + dβββ(with d = deviation from 7)
Then
βMean = A + (sum of deviations)/n
Calculate the deviations:
βFor 4:βd = 4 β 7 = β3
βFor 7:βd = 7 β 7 = 0
βFor 5:βd = 5 β 7 = β2
βFor 9:βd = 9 β 7 = 2
βFor 8:βd = 8 β 7 = 1
βFor 3:βd = 3 β 7 = β4
βFor 6:βd = 6 β 7 = β1
Sum of deviations = (β3) + 0 + (β2) + 2 + 1 + (β4) + (β1) = β7
Now,
βAssumed mean = 7 + (β7)/7 = 7 β 1 = 6
βββββββββββββββββββββββββββββ
Summary of Answers
1. Mean = 6
2. Mode = None (each value occurs once)
3. Median = 6
4. First moment (about the origin) = 6
5. Second moment (about the origin) = 40
6. βOnginβ (variance, the second central moment) = 4
7. Assumed mean (using 7 as the assumed value) = 6
These are the results for the given data set.
Answered by UpStudy AI and reviewed by a Professional Tutor

Explain

Simplify this solution