Question

4. Find the following from standard normal distribution table: (4 marks) a) The Z- value such that there is a 60% probability of a value falling to the left of z. (2 Marks) .7454 (2 Marks) b) The probability that a value will be more than z= -2.3 0094

Answer 1

a) iet to F( 2. z N(011) find a suct that ):0.60 02 on to hnd z we have to look at the Starry nowe table at male boy of table Search for the value 0.60 or the value which is most closer to 0.6o. As we see b.$987, and 0.6026 Ce most closest to 0.60 0.5987 is in now number = 0.2 Column number 0.05. 0.5367 ppresent X = 0.2+0.05 -0.25 0.6026 is in row number = 0.2 Celumn numbers 0.06 0.6626 represent Z2=0.270.06 = 0.26 2 21+22 -0.25 +0.26 - D.SI z = 0.255

P(Z 7,-2.3) = 1-P[26-2.3) from standard Normal table we get the probability less than 2.3. for that purpose, look at the table Now number - - 2.2 or soft cot drone coloumn number = 0.00 the value is = 0.0107 torn e P(Z <-2.3) = 0.0107 Required probability, P(Z > -2.3) = 1-PC25-2-3) - *- 0.0107 - 0.9893