50 POINTS I NEED THIS IM CONFUSED

2. The Welcher Adult Intelligence Test Scale is composed of a number of subtests. On one subtest, the raw scores have a mean of

IgorC [24]

Answer:

a) 37.31 b) 42.70 c) 0.57 d) 0.09

Step-by-step explaanation:

We are regarding a normal distribution with a mean of 35 and a standard deviation of 6, i.e., $\mu$ = 35 and $\sigma$ = 6. We know that the probability density function for a normal distribution with a mean of $\mu$ and a standard deviation of $\sigma$ is given by

$f(x) = \frac{1}{\sqrt{2\pi}\sigma}\exp[-\frac{(x-\mu)^{2}}{2\sigma^{2}}]$

in this case we have

$f(x) = \frac{1}{\sqrt{2\pi}6}\exp[-\frac{(x-35)^{2}}{2(6^{2})}]$

Let $X$ be the random variable that represents a row score, we find the values we are seeking in the following way

a) we are looking for a number $x_{0}$ such that

$P(X\leq x_{0})$ = $\int\limits^{x_{0}}_{-\infty} {f(x)} \, dx = 0.65$ , this number is $x_{0}$ =37.31

you can find this answer using the R statistical programming languange and the instruction qnorm(0.65, mean = 35, sd = 6)

b) we are looking for a number $x_{1}$ such that

$P(X\leq x_{1})$ = $\int\limits^{x_{1}}_{-\infty} {f(x)} \, dx = 0.9$ , this number is $x_{1}$ =42.70

you can find this answer using the R statistical programming languange and the instruction qnorm(0.9, mean = 35, sd = 6)

c) we find this probability as

$P(28\leq X\leq 38)$ = $\int\limits^{38}_{28} {f(x)} \, dx = 0.57$

you can find this answer using the R statistical programming languange and the instruction pnorm(38, mean = 35, sd = 6) -pnorm(28, mean = 35, sd = 6)

d) we find this probability as

$P(41\leq X\leq 44)$ = $\int\limits^{44}_{41} {f(x)} \, dx = 0.09$

you can find this answer using the R statistical programming languange and the instruction pnorm(44, mean = 35, sd = 6) -pnorm(41, mean = 35, sd = 6)

6 0

3 years ago

Read 2 more answers

Carolyn is building a pen for a dog. The PERIMETER of the pen is 52 ft. The material is sold by the yard. It is 10.99 dollars pe

Mazyrski [523]

We know that the fence is 52 feet long, but since it's sold in yards, we need to somehow convert feet to yards.
First, we need to find a little something called a conversion factor. Basically, we need to see what we can do to get from one foot to one yard.
Well, how many feet are there in a yard? 3. So now we know that one foot is 1/3 of a yard.

So to convert 52ft to yards, we need to divide by 3. What's 52 divided by 3?
17.33.
Now we just need to multiply that by 10.99 so that we can find out the cost.
We get 190.45. That's your answer!

It all cost $190.45

Don't forget to rate this answer the Brainliest!

8 0

3 years ago

Xpressions

zlopas [31]

you do parentheses first so 32-8=24
4+2=6

answer 24=6

8 0

3 years ago

Given f '(x) = (x + 1)(6 + 3x), find the x-coordinate for the relative minimum on the graph of f(x).

FinnZ [79.3K]

Answer:

x = -1

Step-by-step explanation:

The easiest way is just to find the antiderivative and graph. The antiderivative is $x^{3} + 4.5x^{2} + 9x + C$ . Graphing this with any C shows that $x=-1$ is the relative minimum.