Answer to Question #113679 in Statistics and Probability for Katenda

Question

Question 17

The sum of deviations about the mean is always?

(1) Zero.
(2) Total standard deviation.
(3) Positive.
(4) Negative.
(5) Range.

Question 18

If the population variance is 4, then the population standard deviation must be?

(1) 4
(2) 16
(3) 2
(4) 0
(5) 12


Question 25

Which one of the following statements is incorrect?

(1) If an event has a probability of 0:25, then the event has a 25% chance of occurring.
(2) A probability is a chance of an event not occurring.
(3) When two events are mutually exclusive, they cannot occur together.
(4) When two events are independent, they can occur together but they do not influence each
other.
(5) The intersection of two events A and B is denoted as P.A and B/.

Answer 1

Question 17) (1) Zero

The sum of the deviations from the mean is zero. This will always be the case as it is a property of the sample mean, i.e., the sum of the deviations below the mean will always equal the sum of the deviations above the mean.

Question 18) (3) 2

Standard deviation it is the square root of the variance

Question 25) (2) A probability is a chance of an event not occurring. 

It is a chance of occurring.