In: Statistics and Probability
State whether each of the statements below is TRUE or
FALSE.
1.1. The scientific approach to decision making can be summarised
as: Data Hypothesis Conclusion
1.2. Exponential smoothing is a method suitable for forecasting
data with no trend or seasonal pattern.
1.3. Experimentation refers to the manipulation of variables under
controlled conditions.
1.4. The linear regression line for a set of data is given as ?= –
17 + 1.2?. It thus follows that there is a direct relationship
between ? and ?.
1.5. The outcome of a patient’s blood type test is an example of a
binomial experiment.
1.6. Approximately 95% of the area below the normal distribution
curve lies between ?=−3 and ?=+3.
1.7. The sales percentage per region per office is quantitative and
continuous.
1.8. A frequency table shows the number of occurrences of a
variable falling into a specific range or category.
1.9 A correlation coefficient of +1 means perfect negative linear
correlation.
1.10 Any sampling method in which the observations are not selected
randomly is called non-probability sampling.
Note : allowed to solve the first four questions.
1.1. The scientific approach to decision making can be
summarised as: Data Hypothesis Conclusion
Correct answer : False, The scientific approach to decision making
can be summarised as Goal Model Data Evaluation Revision
1.2. Exponential smoothing is a method suitable for
forecasting data with no trend or seasonal pattern.
Correct answer : True
1.3. Experimentation refers to the manipulation of
variables under controlled conditions
Correct answer : True.
1.4. The linear regression line for a set of data is
given as ?= – 17 + 1.2?. It thus follows that there is a direct
relationship between ? and ?.
Correct answer : True, x and y are linear correlated. One
unit increase in x, increases y by 1.2 units.
1.5. The outcome of a patient’s blood type test is an
example of a binomial experiment.
Correct answer: False, a binomial experiment there must be only two
outcomes, success and failure but in blood group type there more
than 2.
1.6. Approximately 95% of the area below the normal
distribution curve lies between ?=−3 and ?=+3.
Correct answer : False - Approximately 95% of the area below the
normal distribution curve lies between ?=−2 and ?=+2. 97.5 % of the
area lies between z = -3 and z = 3