Business Statistics 2 (MGTC3111)
Higher Institute of Commerce and Management (HICM)
Semester: First Semester
Level: 300
Year: 2016
NAME
DEPARTMENT
Instructions tick the right answer or fill in the blank spaces where necessary
No calculation must be done on this paper (T=TRUE, F=FALSE
TIME ALLOWED: 50 MINUTES
1. P (A/B)=0.6 and P(A)=0.2, hence A and B are independent. TRUE FALSE
2. The sum of the probabilities, P
X1
, p
X2
……….. P
Xm
always greater than one TRUE
FALSE
3. Binomial and normal distributions are examples of discrete probabilities distribution TRUE
FALSE
4. The rate at which accidents occur at Bambui-Bambili stretch of the road is 2 accidents per day
a. The probability that three accidents will occur in a days is…………………………………….
b. The probability that 4 accidents will in two days is……………………………………...........
5. Study the following table
X
0
1
2
3
4
Probability of X
2K
K
3K
1.5K
2.5K
a. The value of K is-----------------------------------------------------------
b. The E(X) is-----------------------------------------------------------------
6. A statistics is a characteristics of------------------------------as a parameter is for----------------
7. Random variables change with the samples, TRUE FALSE
8. If the population is finite then Var(X) (
)
FALSE
9. Unbiasedness requires that----------------------------------------------------------------------------------------
10. A simple random sample of size two' is drawn from a. population with elements (0,2,5,6,9) the sample
means are……………………………….
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A simple Size of 9 is drawn from a population that is normally distributed with variance 16 and 6.5, the
Standard deviation of the sampling distribution of mean
is…………………………………………………………………………….
11. If the sample mean is 4.6, the sample size 36; While the population mean is 3.9 and the variance
9.9 the standardized value (Z)
is……………………………………………………………………………
12. Efficiency of sample one over Sample two require that………………………………………
13. Suppose a population consists of the element (1,3,5,7). A simple two elements is drawn,
determine the sampling distribution of means and hence, find a) the population mean and
variance b) the mean and standard deviation of sample distribution.
14. The starting salaries of MBA students from two universities (UB and UBa) and $62,000 ( Stand.
Dev=$60,000 (stand. Dev =$18,300). What is the probability that a sample mean of UB students
will exceed the sample mean of UBa students? (number of UB student =50, number of UBa
students=60)
16. A standardized chemistry test was given to 50 girls and 75 boys. The girls made an average grade of
76 with a standard deviation of 6, while the boys made an average grade Of 82 with a standard deviation
of 8.confidence interval for the µ
2
and µ
1
where µ
1
: P2 is the mean score of (all girls..What might take this
test)
Given: n
1
= 75, n
2
= 50, X
1
=82, S
1
=8 S
2
=6 (1-a) = 96 a = 0.04
A 95%of confidence interval for P is
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