Download Assignment 2 statistics

Assignment 5
Section 2.3-2.8
2.48:
a) The mean of the 50 women is 50.02 years. The median age is 51 years. The modal age is 54
years.
b) The mean and median indicate that the graph is skewed to the left because the median is
higher than the mean.
c) The modal age is 54, because it was the most frequent age.
2.54
Bars show count s
Count
6
4
2
0
28 33 38 39 41 45 46 47 48 49 50 51 52 53 54 55 56 58 61 64
AGE
2.54:
a) The mean is 4.05, the median is 3.50 and finally the mode is 5.
b) The mean is 3.68, the median is 3.00 and finally the mode is 5. Dropping the largest value
causes the balance of the data to change. It lowers the mean and median.
c) The mean after dropping the two highest and lowest frequencies is 3.69. The advantage of
having a trimmed mean is that it will be more accurate.
2.68:
a) The range for these women is 36 years.
b) The variance of age for these women is 41.530 years.
c) The standard deviation for these women is 6.444 years.
d) If the standard deviation in Europe was 10 years for the most powerful women they would
have more of a variable data set.
2.82:
50
Count
40
30
20
10
2.0
4.0
6.0
8.0
10.0
tim e
a)
The Empirical rule is true for the time distrubution for firms filing for prepackaged bankruptcy.
b)
time
Descriptives
Statistic
2.549
Mean
95% Confidence
Interval for Mean
Lower Bound
Upper Bound
2.024
3.074
5% Trimmed Mean
2.316
Median
1.700
Variance
Std. Deviation
3.342
1.8280
Minimum
1.0
Maximum
10.1
Range
Interquartile Range
Std. Error
.2611
9.1
2.2
Skewness
2.117
.340
Kurtosis
5.777
.668
c)
d) If the company files for a prepackaged bankruptcy plan I would estimate they would only be
bankruptcy for 1.7 months.
2.96:
a) The median score for the ships is 96.50 so the Nautilus Explorer isn’t doing so well with a
score of only 74. The range is 44 so Nautilus Explorer is right on the middle of the range. Sadly
it is still ranked 3rd from last, or 179 out of 182.
b) Rotterdam’s has the third highest score of 98, but so do 31 other cruise lines. 19 cruises have a
score of 99 and 19 have a perfect score of 100. This places Rottersdam’s somewhere between
39-70 in ranking.
2.108:
a) The 25th percentile is around 7.5, the median is about 10 and the 75th percentile is about 22.5
before treatment.
b) The 25th percentile is around 1.25, the median is about 2.5 and the 75th percentile is about 3.75
after treatment.
c) The effect of ichthyotherapy therapy for treating psoriasis is super effective. The highest score
after the therapy is below the lowest score before the therapy. Everybody must have had better
scores for this to happen.
Section 3.1-3.6
3.18:
a) There are 56 different possibilities to choose from. 8!/(2!)(6!)=56
b) The probability of winning is 2 out of 56. 2/56x100= 3.57%
3.24:
a) There is a 37.73% change of a false negative. 693/1837x100=37.7245
I would not have confidence in the FBI forensic evidence.
3.44:
a) The probability that a wheelchair user had an injurious fall is 15.69%. 48/306x100=15.6862
b) The probability that a wheelchair user had all five modifications in their home is 2.94%.
9/306x100=2.9411
c) The probability that a wheelchair user had no falls and no modifications added to their home is
29.08%. 89/306x100=29.0849
3.70:
a) The probability that the lie detector will determine the veracity is 95.92. 4/98x100=4.08 so
100-4.08=95.92
c) If 2 out of the four test subjects had incorrect results the 98% accuracy could be off. The odds
of two out of four people scoring incorrectly are pretty small but I would recommend testing a
larger sample to see if the results were still as inaccurate before making my judgment.
3.72:
Scott McNeil
201006489