Kapitel 6

Question 1

Which of the P(x) and F(x) is for the discrete random variable and continouos random variable?

Answer 1

P(x)= discrete random variable.

F(x)= continuous random variable.

Question 2

Explain uniform probability distibution:

Answer 2

Alla värden i ett interval har lika stor chans att förekomma.

The probability is proportional.

Question 3

Explain a unifrom probability density function:

Answer 3

Antingen en graf eller formel.

Visar att sannolikheten för alla värden är samma inom intervallet.

Question 4

How do you compute the expected value, E(X) for a uniform continuous probability distibution?

Answer 4

E(X)= (a + b)/2

Question 5

How do you compute the variance, Var (X), for a uniform continuous probability distibution?

Answer 5

Var(X)= (b-a)^2 /12

Question 6

A “perfect” normal curve do have the same three things in the same point, which?

Answer 6

Median, mode and mean.

Question 7

What does a normal curve with mean= 0 and standard deviation of 1, called?

Answer 7

A standard normal probability distribution.

Question 8

What is the formula to convert to the standard normal distibution?

Answer 8

Z= (X-u)/standard deviation.

Question 9

Vad innebär “normal approximation of bionomial probabilites”?

Answer 9

När värderna i bionoimial probabilities blir för stora kan man istället använda bionomial approximation.

Question 10

Vad innebär “continuity correction factor” inom bionomial approximation?

Answer 10

Man lägger på och tar bort 0,5 för att kunna mäta arean.

Question 11

Which two proportions need to be true to use the normal approximation of bionomial probabilities?

Answer 11

1. n x pi större än 5.
2. n(1 - pi) måste vara större än 5.