Which expression will make the equation true -4.5+4.4+x=0

Assume the random variable X is normally distributed with mean mu equals 50 and standard deviation sigma equals 7. Compute the p

drek231 [11]

Answer:

The probability that X is less than 42 is 0.1271.

Step-by-step explanation:

The random variable X follows a Normal distribution.

The mean and standard deviation are:

E (X) = μ = 50.

SD (X) = σ = 7.

A normal distribution is continuous probability distribution.

The Normal probability distribution with mean µ and standard deviation σ is given by,

$f_{X}(\mu, \sigma)=\frac{1}{\sigma\sqrt{2\pi}}e^{-(x-\mu)^{2}/2\sigma^{2}};\ -\infty$

To compute the probability of a Normal random variable we first standardize the raw score.

The raw scores are standardized using the formula:

$z=\frac{x-\mu}{\sigma}$

These standardized scores are known as z-scores and they follow normal distribution with mean 0 and standard deviation 1.

Compute the probability of (X < 42) as follows:

$P(X$

*Use a z-table for the probability.

Thus, the probability that X is less than 42 is 0.1271.

The normal curve is shown below.

6 0

3 years ago

Evaluate using Definite integrals

swat32

Since $[0,4]=[0,1]\cup(1,4]$ , we can rewrite the integral as

$\displaystyle \int_0^1f(t)\;dt + \int_1^4 f(t)\; dt$

Now there is no ambiguity about the definition of f(t), because in each integral we are integrating a single part of its piecewise definition:

$\displaystyle \int_0^1f(t)\;dt = \int_0^11-3t^2\;dt,\quad \int_1^4 f(t)\; dt = \int_1^4 2t\; dt$

Both integrals are quite immediate: you only need to use the power rule

$\displaystyle \int x^n\;dx=\dfrac{x^{n+1}}{n+1}$

to get

$\displaystyle \int_0^11-3t^2\;dt = \left[t-t^3\right]_0^1,\quad \int_1^4 2t\; dt = \left[t^2\right]_1^4$

Now we only need to evaluate the antiderivatives:

$\left[t-t^3\right]_0^1 = 1-1^3=0,\quad \left[t^2\right]_1^4 = 4^2-1^2=15$

So, the final answer is 15.

4 0

3 years ago

How do you sovle for b w= 2a + 3b

raketka [301]

Hope This helps you..!!!!

5 0

3 years ago

The formula equals 16t squared is used to approximate the distance s, in feet, that an object falls freely from rest in t seco

Brut [27]

The equation is actually $h(t)=-16t^2+1437$ . Free fall is always -16t^2 as the position function. We are looking for how long it takes the object to hit the ground. In other words, the height of an object is 0 when it is laying on the ground, so how long (t) did it take to get there? We will then set that position equal to 0 and solve for t. $0=-16t^2+1437$ . If we subtract 1437 from both sides and divide by -16, we have $t^2=89.8125$ . Taking the square root of both sides gives us, rounded to the nearest tenth, t = 9.5 or t=-9.5. The 2 things in math that will never EVER be negative are time and distance/length, so -9.5 is out. That means that it took just about 9.5 seconds for the object to fall to the ground from a height of 1437 feet when pulled on by the force of gravity.

6 0

3 years ago

Thru (4,0) parallel to y=1/2x+5

Ne4ueva [31]

Paralell has same slope
y=mx+b
m=slope
y=1/2x+b
find b
(x,y)
(4,0)

x=4
y=0
0=1/2(4)+b
0=2+b
minus 2 both sides
-2=b

the equaiton is
y=1/2x-2
or
x-2y=4

7 0

2 years ago