Statistics and Probability Answers

A normal distribution has the mean of 150.5. if 70.54% of the area under the curve lies to the left of 177.5 find a. the standard deviation?​

A satellite can fail for many possible reasons, two of which are computer failure and engine failure. F or a given mission, it is known that: The probability of engine failure is 0.008. The probability of computer failure is 0.001. G iven engine failure, the probability of satellite failure is 0.98. G iven computer failure, the probability of satellite failure is 0.45. G iven any other component failure, the probability of satellite failure is zero. (a) D etermine the probability that a satellite fails. (b) D etermine the probability that a satellite fails and is due to engine failure. (c) Assume that engines in different satellites perform independently. G iven a satellite has failed as a result of engine failure, what is the probability that the same will happen to another satellite?

dem0graphic profile of ecuator in 2018

27.08% population are 0-14 years old

18.35% population are 15-24 years old

39.59 population are 25-54 years old

7.53% population are 55-64 years old

7.45% population are 65 years old

number of random sample of 20 people .what is probability that 2 are 65 years ols, 5 are 55-64 years old, 6 are 25-54 years old ,the number of random sample that have composition like that one described above is________.Each of those random sample have a probability of occuring of _________the probability of event containing all random samples that fit the description above is______________

options

a) 97772875200

b)1.1649

c)0.0001138

d)349186

e)0.319

A veterinary nutritionist developed a diet for overweight dogs. The total volume of food

consumed remains the same, but one half of the dog food is replaced with a low-calorie

“filler” such as canned green beans. Six overweight dogs were randomly selected from

her practice and were put on this program. Their initial weights were recorded, and then

they were weighed again after 4 weeks. At the 0.05 level of significance can it be

concluded that the dogs lost weight?

Before 42 53 48 65 40 52

After 39 45 40 58 42 47

a. State the hypothesis and identify the claim of the researcher.

b. Find the critical value(s).

c. Compute for the mean of the differences, standard deviation of the differences

and test value.

d. Make a decision on the null hypothesis.

e. Make a decision on the claim of the researcher.

Suppose that X is a random variable with MGF Mx(t) = (1/8)e^t + (l/4)e^t2 + (5/8)e^t5. a)What is the distribution of X?

b)What is P[X = 2]?

Let X be continuous with pdf(x) = 3x^2 if 0 < x < 1, and zero otherwise,

a) Find E(X).

b)Find Var(X).

c)Find E(X').

d)Find E(3X - 5X^2 + 1).

A random variable X has a CDF such that

F(x)= ( x/2 0<x≤1

( (x-1/2 1<x≤3/2

a)Graph F(x).

b/Graph the pdf f(x).

c)FindP[X≤1/2].

d)Find P[X  ≥1/2].

e)Find P[X≤ 1.25].

f)What is P[X= 1.25]?

A function f(x) has the following form:

f(x)=kx 1<x<∞

and zero otherwise.

a)For what values of k is f(x) a pdf?

b)Find the CDF based on (a).

c)For what values of k does E(X) exist?

A chef at an amusement park feels that the amount of time that people spend waiting in line to get served is too long. To determine if a new waitng procedure is effective in reducing the wait time, she measures the amount of time (in minutes) people are waiting in line for seven days. 

                                 Mon         Tues        Wed         Thurs        Fri            Sat           Sun

Wait time before        12            26            20             38            57            82             57

Wait time after           11            28            19             36            59            75             55

Is the new waiting  procedure effective in reducing the wait time at the =0.05 level of significance?

1. State the hypothesis and identify the claim.
2. Find the critical value(s)
3. Compute the Test value
4. Make a decision on the null hypothesis
5. Make a decision on the claim