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The purpose of a study by Lugli_e et al. (A-5) was to investigate the oral
status of a group of patients
diagnosed with thalassemia major (TM). One of the outcome measures was
the decayed, missing, and
filled teeth index (DMFT). In a sample of 18 patients the mean DMFT index
value was 10.3 with a
standard deviation of 7.3. Is this sufficient evidence to allow us to conclude
that the mean DMFT
index is greater than 9.0 in a population of similar subjects? Let alpha = 0.1
The table below gives the scores of Students on a English Examinations
under KCSE
Student
1
2
3
4
5
6
7
8
9
Oral test
B-
B+
B
A-
A
B
C+
B
C-
Composition
10
21
22
19
17
14
13
16
12
Literature
34
76
74
60
68
44
45
53
43
(Composition test is out of 30 and literature test is out of 100 marks)
(a) Calculate the value of the most appropriate measure of correlation between the results
in the oral and composition tests, justifying your choice of measure. Interpret the value you
obtain.
(b) Calculate the value of the most appropriate measure of correlation between the results in
the composition and literature tests, justifying your choice of measure. Interpret the value
you obtain.
A solid square rod is cantilevered at one end. The rod is 0.6 m long and supports a completely reversing transverse load at the other end of ±2 kN. The material is AISI 1080 hot-rolled steel. If the rod must support this load for 104 cycles with a factor of safety of 1.5 at 100°C, what dimension should the square cross section have? Neglect any stress concentrations at the support end.
The shaft shown in the figure is machined from AISI 1040 CD steel. The shaft rotates at 1600 rpm and is supported in rolling bearings at A and B. The applied forces are F1 = 2500 lbf and F2 = 1000 lbf. Determine the minimum fatigue factor of safety based on achieving infinite life. If infinite life is not predicted, estimate the number of cycles to failure. Also, check for yielding.
A stepped shaft, as shown in figure made from BS080M50 cold drawn steel is subjected to a completely reversed torque T. Based on infinite life, 90% reliability and a factor of safety of 2.1, find the maximum allowable safe torque T, that can be applied, if d = 8 mm.
The figure shows the free-body diagram of a connecting-link portion having stress concentration at three sections. The dimensions are r = 0.25 in, d = 0.40 in, h = 0.50 in, w1 = 3.50 in, and w2 = 3.0 in. The forces F fluctuate between a tension of 5 kip and a compression of 16 kip. Neglect column action and find the least factor of safety if the material is cold-drawn AISI 1018 steel.
The cold-drawn AISI 1040 steel bar shown in the figure is subjected to a completely reversed axial load fluctuating between 28 kN in compression to 28 kN in tension. Estimate the fatigue factor of safety based on achieving infinite life and the yielding factor of safety. If infinite life is not predicted, estimate the number of cycles to failure.
You are testing a new amusement park roller coaster with an empty car with a mass of 110 kg
kg . One part of the track is a vertical loop with a radius of 12.0 m
m . At the bottom of the loop (point A
A) the car has a speed of 25.0 m/s
m/s and at the top of the loop (point B
B) it has speed of 8.00 m/s
m/s .
Which option is true of a team leader?
Select one:
a. may have both project management duties and some technical duties
b. works primarily on projects in which the all business functions are interdependent
c. primarily leads big IT projects
d. has high to almost total authority
Exactly different organisms such as fish and humans may have resembles during early stage of their development and will lose some key likeness as they grow in the later stage of development
