Answer:
its a
Step-by-step explanation:
Answer:
The answer is explained below
Step-by-step explanation:
Given that:
mean (μ) = 7 and standard deviation (σ) = 1.5.
The z score is used in statistic used to measure the number of standard deviation by which the raw score is above or below the mean value. It is given by:

To find the Probability that x < 8.8, we first find the z score using:

From the z tables, P(x < 8.8) = P(z < 1.2) = 0.8849 = 88.49%
Answer:
Step-by-step explanation:
given that on a six-question multiple-choice test there are five possible answers for each question, of which one is correct and four are incorrect
By mere guessing probability for choosing correct answer = p = 0.2
also each question is independent of the other
Hence if X is the number of correct questions then
X is binomial with p = 0.2 and n = 6
a) being correct on three questions,
=
(b) being correct on four questions,
= 
(c) being correct on all six questions
=
10(-1c+7)-3c
(-10c+70)-3c
-13c+70 is your answer