Question

For a standard normal distribution, find:

P(z > -0.86)

P(z > c) = 0.3338. Find C.

P(z > -0.86)

Answer 1

Answer:

Step-by-step explanation:

Given that a variable follows a standard normal distribution

Z is N(0,1)

Thus we can use the standard normal distribution table to find the required probabilities or c

a) $P(z > -0.86)$

We know std normal is symmetric about 0.  Hence this prob is area from 0 to end on right side and 0 to 0.86 on left side

= sum of two prob = 0.3051+0.5=0.8051

b) $P(z > c) = 0.3338$

Since prob is less than 0.5 we find that c lies to the right of 0. i.e.c is positive

Between 0 and c prob $= 0.5-0.3338 = 0.1662$

Seeing the table we find that c = 0.43