Reference no: EM132845872
1. We are flipping a coin 6 times. What is the probability of the outcomes to be: (Binomial distribution).
a) two tails.
b) At least 5 tails.
c) The most 2 heads
2. Let us assume that you take a multiple choice test with 20 questions, and each question consist of 4 answers (a,b,c,d). What is the probability of getting exactly 8 questions correct? (Binomial distribution).
3. In the USA, voters who do not vote the Democratic Party or the Republican Party is called Independent. They are approximately 10% of the electorate. If we randomly choose 10 voters: (Binomial distribution).
a) What is the probability 5 of them to be Independent?
b) What is the probability less than 3 to be independent?
c) What is the probability at least 8 to be independent?
4. Using the z-table:
a) Find the area that lies to the left of = 0.24.
b) Find the area that lies to the right of = -2.3.
c) Find the area that lies between Z1 = -1.15 and Z2 = 2.7
5. The random variable is normally distributed and presents the usage of the tyres of a car (in thousand kilometres) with a mean usage = 50 and standard deviation = 5. What is the probability that the tyres will endure:
a) Less than 39,2 thousand kilometres.
b) Between 40 and 60 thousand kilometres.
6. Let us assume that the grades of 500 students are normally distributed with = 45 and standard deviation = 20. If the 20% of the students get excellent, what is the grade that determines the excellent? (What is value?)