All categories

2 years ago

If the value of "y" varies directly with "X" and y = -8 when x = 20, find "y" if x = -4.

Mathematics

1 answer:

natka813 [3]2 years ago

5 0

Answer:

y = 10 when x is -4

will be the correct answer

You might be interested in

A simple random sample of size nequals81 is obtained from a population with mu equals 83 and sigma equals 27. (a) Describe the

Ivanshal [37]

Answer:

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

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

b) $z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

c) $z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

d) $z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

Step-by-step explanation:

For this case we know the following propoertis for the random variable X

$\mu = 83, \sigma = 27$

We select a sample size of n = 81

Part a

Since the sample size is large enough we can use the central limit distribution and the distribution for the sampel mean on this case would be:

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

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

Part b

We want this probability:

$P(\bar X>89)$

We can use the z score formula given by:

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

And if we find the z score for 89 we got:

$z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

Part c

$P(\bar X$

We can use the z score formula given by:

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

And if we find the z score for 75.65 we got:

$z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

Part d

We want this probability:

$P(79.4 < \bar X < 89.3)$

We find the z scores:

$z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

8 0

3 years ago

Jon ran 4 miles in 35<br> minutes. How long did it<br> take him to run a mile

sesenic [268]

Answer:

35/4 minutes per mile

Step-by-step explanation:

rate = time/distance, therefore the answer is 35/4

4 0

2 years ago

Can someone answer this !

rodikova [14]

Answer:

11253

Step-by-step explanation:

the steps are described in the picture above

6 0

2 years ago

No chi-square The principal in Exercise 7 also

larisa [96]

The random sample of the students is an illustration of sampling

The chi-square test for goodness of fit is inappropriate because the variable under study is not categorical.

<h3>How to determine the reason chi square is not appropriate?</h3>

The dataset is given as:

Monday 34

Tuesday 29

Wednesday 32

Thursday 28

Friday 19

The variable of the above dataset is a not a categorical dataset.

One of the conditions of the chi-square test for goodness of fit test is that the variable under study must be categorical.

Hence, the chi-square test for goodness of fit is inappropriate because the variable under study is not categorical.