Some students are making

A used bookstore sells hardback books and paperback books.A hardback book costs $11, including tax.A paperback book costs $5, in

Ket [755]

Answer:

D.5

Step-by-step explanation:

You can write the following equations from the information given:

y=x+3 (1)

11x+5y=47 (2)

x is the number of hardback books

y is the number of paperback books

You can replace (1) in (2):

11x+5(x+3)=47

11x+5x+15=47

16x=47-15

16x=32

x=32/16

x=2

Then, you can replace the value of x in (1) to find the value of y:

y=2+3

y=5

According to this, the answer is that Jamal bought 5 paperback books.

6 0

3 years ago

Given a population with a mean of muμequals=100100 and a variance of sigma squaredσ2equals=3636, the central limit theorem appl

lakkis [162]

Answer:

a) $\bar X \sim N(100,\frac{6}{\sqrt{25}}=1.2)$

$\mu_{\bar X}=100$ $\sigma^2_{\bar X}=1$

b) $P(\bar X >101)=1-P(\bar X$

c) $P(\bar X$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".

The complement rule is a theorem that provides a connection between the probability of an event and the probability of the complement of the event. Lat A the event of interest and A' the complement. The rule is defined by: $P(A)+P(A') =1$

Let X the random variable that represent the variable of interest on this case, and for this case we know the distribution for X is given by:

$X \sim N(\mu=100,\sigma=6)$

And let $\bar X$ represent the sample mean, by the central limit theorem, the distribution for the sample mean is given by:

$\bar X \sim N(\mu,\frac{\sigma}{\sqrt{n}})$

a. What are the mean and variance of the sampling distribution for the sample means?

$\bar X \sim N(100,\frac{6}{\sqrt{25}}=1.2)$

$\mu_{\bar X}=100$ $\sigma^2_{\bar X}=1.2^2=1.44$

b. What is the probability that x overbarxgreater than>101

First we can to find the z score for the value of 101. And in order to do this we need to apply the formula for the z score given by:

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

If we apply this formula to our probability we got this:

$z=\frac{101-100}{\frac{6}{\sqrt{25}}}=0.833$

And we want to find this probability:

$P(\bar X >101)=1-P(\bar X$

On this last step we use the complement rule.

c. What is the probability that x bar 98less than

First we can to find the z score for the value of 98.

$z=\frac{98-100}{\frac{6}{\sqrt{25}}}=-1.67$

And we want to find this probability:

$P(\bar X$

5 0

3 years ago

Solve For X Help me please

Lapatulllka [165]

Answer is A

Once you add 29 to negative 34 you will get negative 5 and then divide 5 and you will end up with negative 1 always flip the sign when dealing with a negative

3 0

3 years ago

Read 2 more answers

1 point<br> Solve using order of operations.<br> 23.4+ (7-3)<br> O 28

Vilka [71]

Answer:

Step-by-step explanation:

Do the answer is 67’949

5 0

3 years ago

Rectangle ABCD is translated (x + 2 y - 3) and then rotated 180° about the origin. Complete the table to show the locations of A

katen-ka-za [31]

Answer:

A

Step-by-step explanation:

4 0

3 years ago