Consider the experiment of tossing a fair coin three times and observing the number of heads that result (X = number of heads).
1 answer:
Answer:
The standard deviation for this distribution is 0.8660.
Step-by-step explanation:
For each coin toss, there are only two possible outcomes. Either it is heads, or it is tails. So we use the binomial probability distribution to solve this problem.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The standard deviation of the binomial distribution is:
In this problem, we have that:
In each toss, heads or tails are equally as likely, since the coin is fair. So
Three throws, so
What is the standard deviation for this distribution?
The standard deviation for this distribution is 0.8660.
You might be interested in
The discriminant of this equation is 49. The solutions for this equation are x=2 and x=-
I hope that helps.
I hope that helps.
Answer:
The solutions for your four question problem are:
a) t = D^-1(x) = (1/57)*x -(13/57)
b) t = D^-1(x) = 1 h
c) D^-1(x) represents time.
d) The number of hours of driving needed for Sarah to be x km from Tempe. (option (c))
Step-by-step explanation:
a) Determine a formula in terms of x for: t = D^-1(x)
The distance in km from Tempe after t hours of driving is given by
x = D(t) = 13 + 57t.
We just need to find the value t function of x
x = 13 + 57*t
x -13 = 57*t
57*t = x -13
t = (1/57)*x -(13/57)
We can see the plots of both equation in the picture below.
b) Compute D^-1(70)
Once we find the expression for D^-1(x)
We substitute for x = 70 km
t = D^-1(x) = (1/57)*x -(13/57)
t = D^-1(x) = (1/57)*(70) -(13/57)
t = D^-1(x) = (70/57) -(13/57)
t = D^-1(x) = (1.228) -(0.228)
t = D^-1(x) = 1 h
c) In the expression D^-1(x) : what quantity (distance or time) does the x represent? what quantity (distance or time) does the entire D^-1(x) represent?
x represents Distance in both equations (D(t), and D^-1(x))
t represents Time in both equations (D(t), and D^-1(x))
Since t = D^-1(x),
D^-1(x) represents time.
d) Which of the following statements best describes D^-1(x)?
The number of hours of driving needed for Sarah to be x km from Tempe.
Since, t = D^-1(x), and t represents the amount of time elapsed since Sarah, parted from Tempe, the correct answer is option (c)
The expression for D^-1(x) can be found in the previous answers
t = D^-1(x) = (1/57)*x -(13/57)
The input is x (distance) and the output is t (time)
