4x – 13 < 11 Help!! Please

a couch sells for $1260. instead of paying the toatl amount at the time of the purchase, the same couch can be brought by paying

bixtya [17]

If you pay $400 down, plus $80 for the next 12 months, that means you're paying (80*12)+400 which is equal to $1360. You're saving $100 by paying the entire total up front.

4 0

3 years ago

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The temperature in Bloomington on Sunday was 32.6°C. On Monday, the temperature changed by -8.25°C. What was the temperature on

gulaghasi [49]

Your answer should be C

6 0

3 years ago

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A random sample of 36 observations has been drawn from a normal distribution with mean 50 and standard deviation 12. Find the pr

Gre4nikov [31]

Answer:

$z= \frac{47 -50}{\frac{12}{\sqrt{36}}}=-1.5$

$z= \frac{53 -50}{\frac{12}{\sqrt{36}}}=1.5$

And using a calculator, excel ir the normal standard table we have that:

$P(47 \leq \bar X \leq 53) =P(-1.5 \leq Z \leq 1.5)$

And we can calculate the probability like this: $P(-1.5 \leq Z \leq 1.5) = P(z$ Step-by-step explanation:

A random sample of 36 observations has been drawn from a normal distribution with mean 50 and standard deviation 12. Find the probability that the sample mean is in the interval 47<=X<53. Is the assumption of normality important. Why?

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".

Solution to the problem

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

$X \sim N(50,12)$

Where $\mu=50$ and $\sigma=12$

Since the distribution for X is normal then we know that the distribution for the sample mean $\bar X$ is given by:

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

We can find the probability required like this:

$z= \frac{47 -50}{\frac{12}{\sqrt{36}}}=-1.5$

$z= \frac{53 -50}{\frac{12}{\sqrt{36}}}=1.5$

And using a calculator, excel ir the normal standard table we have that:

$P(47 \leq \bar X \leq 53) =P(-1.5 \leq Z \leq 1.5)$

And we can calculate the probability like this:

$P(-1.5 \leq Z \leq 1.5) = P(z$

4 0

3 years ago

How many lines of symmetry does this regular polygon have A.0 B.1 C.2 D.5

REY [17]

Answer:

c

Step-by-step explanation:

the top pair and the middle pair

7 0

4 years ago

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Here is a circle, centre O, and the tangent to the circle at the point (-3, 4) on the circle. У P (-3, 4) X -5 O Oา Find an equa

sattari [20]

Answer:

$y=\frac{3}{4}x+\frac{25}{4}$

Step-by-step explanation:

when a line is tangent to a circle, it is perpendicular to the line from the center of the circle to the intersection of the line and the circle. so first we are going to find the slope of the line in the circle.

to find the slope use the formula $\frac{y_2-y_1}{x_2-x_1}$

$\frac{4-0}{-3-0}=\frac{4}{-3}=-\frac{4}{3}$ so the slope is -4/3

the slope of the line perpendicular to this is the opposite reciprocal: 3/4 so now we have y= 3/4 x +b, to find b plug in the point (-3,4) to get 4=-9/4 +b, b=25/4 the equation is y=3/4 x +25/4

4 0

3 years ago