Answer:
a) Expected score on the exam is 12.8.
b) Variance 10.24, Standard deviation 3.2
Step-by-step explanation:
For each question, there are only two possible outcomes. Either you guesses the answer correctly, or you does not. The probability of guessing the answer of a question correctly is independent of other questions. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
The variance of the binomial distribution is:
The standard deviation of the binomial distribution is:
64 questions.
So 
5 possible answers, one correctly, chosen at random:
So 
(a) What is your expected score on the exam?
(b) Compute the variance and standard deviation of x. Variance =Standard deviation
Variance 10.24
Standard deviation 3.2
Answer:
15 kilometers
Step-by-step explanation:
So we know:
For 4 days she runs 1500 meters each day.
For 3 days she runs 3 kilometers each day.
First off, lets convert 1500 meters into kilometers.
There are 1000 meters in a kilometer, so pluggin in 1500 meters:
1500/1000 = 1.5
So for 4 days she runs 1.5 kilometers each day.
Now, to find the total kilometers, we must find multiply the 1.5 kilometers by the 4 days, the 3 kilometers by the 3 days, then add those two together.
So lets do this:
1.5*4 = 6
So she ran 6 kilometers in the first 4 days.
Next we have:
3*3 = 9
So she ran 9 kilometers in the last 3 days.
Now finally add them together:
6 + 9 = 15
So she ran a total of 15 kilometers.
Hope this helps!
Answer:
16
Step-by-step explanation:
4 + 8/2 x 3
4+4 x 3
4+12
16
Hope this helped
Brainliest is appreciated.
Answer:
5 units
Step-by-step explanation:
3x + 4y = 8
4y = -3x+8
y = -3/4+2
The shortest distance between a point and a line is the perpendicular line.
Slope of the perpendicular line: 4/3 and point (-3,-2)
b = -2-(4/3)(-3) = 2
Equation of the perpendicular line: y=4/3x+2
y is equal y
4/3x+2= -3/4x+2
4/3x +3/4x = 2-2
x = 0
Plug x=0 into one of the equations to find y
y = 4/3(0) + 2
y = 2
(0,2) and (-3,-2)
Distance = sqrt [(-3-0)^2 + (-2-2)^2]
Sqrt (-3)^2+ (-4)^2
Sqrt 25 = 5
