# NOUN e-Exams Past Questions and Answers: STT205 – Statistics for Management Sciences I

FBQ1: Any measure indicating the Centre of a set of data, arranged in an increasing or decreasing order of magnitude, is called a measure of: __

Answer: Central tendency

FBQ2: Scores that differ greatly from the measures of central tendency are called:___

Answer: Outliers

FBQ3: The total of all the observations divided by the number of observations is called: __

Answer: Arithmetic mean

FBQ4: The sample mean X- is an example of a: ______

Answer: Statistic

FBQ5: The population mean 渭 is an example of a:

Answer: Parameter

FBQ6: The arithmetic mean is highly affected by: ____

Answer: Extreme values

FBQ7: If a constant value is added to every observation of data, how would the value of the arithmetic mean behave? ____

Answer: Increased by the constant

FBQ8: The median is considered a robust measure because it is resistant to: ____

Answer: Outliers

FBQ9: What effect will the elimination of extreme scores at the bottom of a data set have on the mean? __

Answer: Increase the mean

FBQ10: The elimination of extreme scores at the top of the set has the effect of:

Answer: Reduce the mean

FBQ11: The sum of deviations taken from mean is: _____

Answer: 0

FBQ12: The sum of the squares of the deviations about mean divided by the number of observations is: ____

Answer: Variance

FBQ13: If 鈭慽=110Xi-50=100 then sample mean X- will be: ____

Answer: 60

FBQ14: For a certain distribution, if 鈭�(X聽-20)聽=聽25,聽聽聽鈭�(X-聽25)聽=0, and 鈭�(X-35)聽=聽-25, then X- is equal to:

Answer: 25

FBQ15: The sum of the squares of the deviations of the values of a variable is least when the deviations are measured from: ____

Answer: Arithmetic mean

FBQ16: If X-=100 and Y=2X聽鈥撀�200, then mean of Y values will be: ___

Answer: 0

FBQ17: Step deviation method or coding method is used for computation of the____

Answer: Arithmetic mean

FBQ18: If the arithmetic mean of 20 values is 10, then sum of these 20 values is:___

Answer: 200

FBQ19: Ten families have an average of 2 boys. How many boys do they have together?

Answer: 20

FBQ20: If the arithmetic mean of the two numbers X1 and X2 is 5 if X1=3, then X2 is:___

Answer: 7

FBQ21: Given X1=20 and X2=-20. The arithmetic mean will be: ____

Answer: 0

FBQ22: The mean of 10 observations is 10. All the observations are increased by 10%. The mean of increased observations will be: __

Answer: 11

FBQ23: The frequency distribution of the hourly wage rate of 60 employees of a paper mill is as follows: The mean wage rate is:N____

Answer: 59.00

FBQ24: The sample mean X- of first n natural numbers is: ____ 聽

Answer: (n+1)/2

FBQ25: The sum of deviations is zero when deviations are taken from:____

Answer: Mean

FBQ26: When the values in a series are not of equal importance, we calculate the: _____

Answer: Weighted mean

FBQ27: When all the values in a series occur the equal number of times, then it is not possible to calculate the:____

Answer: Weighted mean

FBQ28: The mean for a set of data obtained by assigning each data value a weight that reflects its relative importance within the set, is called:___

Answer: Weighted mean

FBQ29: The arithmetic mean of 10 items is 4 and the arithmetic mean of 5 items is 10. The combined arithmetic mean is: __

Answer: 6

FBQ30: The midpoint of the values after they have been ordered from the smallest to the largest or the largest to the smallest is called:__

Answer: Median

FBQ31: The first step in calculating the median of a discrete variable is to determine the: ___

Answer: Array

FBQ32: The suitable average for qualitative data is: ____

Answer: Median

FBQ33: If the smallest observation in a data is decreased, the average which is not affected is: __

Answer: Median

FBQ34: Sum of absolute deviations of the values is least when deviations are taken from: ____

Answer: Median

FBQ35: The frequency distribution of the hourly wages rate of 100 employees of a paper mill is as follows: The median wage rate is:N __

Answer: 59.00

MCQ1: The values of the variate that divide a set of data into four equal parts after arranging the observations in ascending order of magnitude are called:

Answer: quartiles

MCQ2: The lower and upper quartiles of a symmetrical distribution are 40 and 60 respectively. The value of median is:

Answer: 50

MCQ3: If in a discrete series 75% values are less than 30, then:

Answer: Third quartile =30

MCQ4: The probability of the amount X (in million Naira) of investment in the shares of ABC Company is given as follows:Find E (X).

Answer: 35/18

MCQ5: The mean of first 2n natural numbers is:

Answer: (2n+1)/2

MCQ6: If X-1,聽X-2,聽X-3,鈥�.X-k be the arithmetic means of k distributions with respective frequencies n1,聽n2,聽n3,聽鈥β�,nk, then the mean of the whole distribution X-c is given by:

Answer: 鈭憂X-鈭憂

MCQ7: The combined arithmetic mean of two sets of means is calculated by which formula?

Answer: n1X-1+n2聽X-2n1+n2

MCQ8: Extreme scores will have the following effect on the median of an examination

Answer: They may have no effect

MCQ9: The probability of the amount X (in million Naira) of investment in the shares of ABC Company of Adewale is given as follows:E(X2). is actually 5.89. What is the variance of X?聽

Answer: 2.11

MCQ10: The grouped frequency distribution shown below is to be used to answer the following questionWhich class is the modal class?

Answer: 20 – 24

MCQ11: The grouped frequency distribution shown below is to be used to answer the following questionWhich class is the median class?

Answer: 20 – 24

MCQ12: The grouped frequency distribution shown below is to be used to answer the following questionWhat is the cumulative frequency of the modal class?

Answer: 14

MCQ13: For a standard normal distribution, what is the values of the mean and variance?

Answer: Mean = 0, variance = 1

MCQ14: Given the set of numbers: 15, 16, 12, 11, 19, 18, 13 then 氓x is,

Answer: 1600

MCQ15: The mean of 63, 19, 52, 10, 95, 18 is

Answer: 42.83

MCQ16: The median of 63, 19, 52, 10, 95, 18 is

Answer: 35.5

MCQ17: The mode and the range of the above data are

Answer: 40, 40

MCQ18: The geometric mean of 6, 8, 10 and 16 is

Answer: 9.36

MCQ19: The harmonic mean of 6, 7, 8 and 9 is

Answer: 7.33

MCQ20: Given that the mean of a distribution is 160, the mode is 150 and the standard deviation is 25. Find the coefficient of skewness

Answer: 0.4

MCQ21: A set of sales from an outlet produced the following: 16, 14, 18, 10, 12 compute the variance

Answer: 8

MCQ22: The coefficient of variation for data set whose mean is 10 and variance 100 is

Answer: 100%

MCQ23: For a symmetric distribution

Answer: The mean, median and the mode are equal

MCQ24: Which statistics is found by summing all the values and dividing by the number of observations?

Answer: The arithmetic mean

MCQ25: How would you describe the skewness of a distribution whose mean is smaller than the median?

Answer: Negatively skewed

MCQ26: What level of measurement is required for the median?

Answer: ordinal

MCQ27: The Nigeria Stock Exchange (NSE) index increased from 961 in 1980 to over 9,500 in 2003. The annual rate of increase is best described by the

Answer: Geometric mean

MCQ28: What is the shape of a frequency distribution with an arithmetic mean of 12,000 pounds, a median of 12,000 pounds, and a mode of 12,000 pounds?

Answer: symmetric

MCQ29: Given that the mean of a distribution is 60, the mode is 50 and the standard deviation is 25. Find the coefficient of skewness:

Answer: 0.4

MCQ30: A set of experimental animals was fed in a special diet for one week and produced the following gains in weight: 6, 4, 8, 10, 12 compute the variance:

Answer: 8

MCQ31: The coefficient of variation for data set whose mean is 16 and variance 10 is

Answer: 19.8

MCQ32: Given the mean = 60 and variance is 625, find the coefficient of variation

Answer: 41.7%

MCQ33: Suppose A and B are independent events with PA=0.2,聽PB=0.6..What is PAB=?

Answer: 0.2

MCQ34: In a shipping organization, it is observed that the total number of items imported is 400 units. If you are to categorise these items into types of commodity with the aid of a pie chart, what angle would 160 units of chemical take?

Answer: 144 degree

MCQ35: The data collected by questionnaires are usually classified as what type of data?

Answer: Primary data