All categories

3 years ago

Pls help will give brainliest

Mathematics

2 answers:

tia_tia [17]3 years ago

4 0

Answer:

Step-by-step explanation:

i dont think were really supposed to be answering something like this... you literally posted a picture of your test...

Firdavs [7]3 years ago

3 0

1st one is 3/17
2nd is 4

You might be interested in

36 3⁄4 gallons of water come out of a hose in 15 minutes. Write the ratio in fractional form and determine the water rate in gal

Brrunno [24]

Answer:

Step-by-step explanation:

If 3⁄4 gallons of water come out of a hose in 15 minutes, to calculate the rate of water that comes out in an hour (60 minutes), we will use the expression;

3/4 gallons = 15 minutes

x gallons = 60minutes

cross multiply

15x = 3/4 * 60

15x = 180/4

15x = 45

x = 45/15

x = 3/1

x = 3:1

Hence the water rate in gallons per hour is 3 gallons per hour

7 0

3 years ago

6) Solve. x + 5 = 10 A) x = 2 B) x = 3 09 x = 4 D) X = 5

LenaWriter [7]

D is the correct answer
x+5=10: subtract 5 from both sides the 5 will cancel out leaving x=5
x+5=10
-5 -5
x=5

4 0

3 years ago

What is the range and domain of f(x)=60-0.18x

Gnom [1K]

The domain is always the value of x, but there is no value of x shown..

3 0

3 years ago

Pre college need help with

kati45 [8]

Answer:

check online for more information

8 0

2 years ago

SAT scores are normed so that, in any year, the mean of the verbal or math test should be 500 and the standard deviation 100. as

vovangra [49]

Answer:

a) $P(X>625)=P(\frac{X-\mu}{\sigma}>\frac{625-\mu}{\sigma})=P(Z>\frac{625-500}{100})=P(Z>1.25)$

$P(Z>1.25)=1-P(Z$

b) $P(400$

$P(-1$

c) $z=-0.842$

And if we solve for a we got

$a=500 -0.842*100=415.8$

So the value of height that separates the bottom 20% of data from the top 80% is 415.8.

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".

Part a

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

$X \sim N(500,100)$

Where $\mu=500$ and $\sigma=100$

We are interested on this probability

$P(X>625)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

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

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

$P(X>625)=P(\frac{X-\mu}{\sigma}>\frac{625-\mu}{\sigma})=P(Z>\frac{625-500}{100})=P(Z>1.25)$

And we can find this probability using the complement rule and with the normal standard table or excel:

$P(Z>1.25)=1-P(Z$

Part b

We are interested on this probability

$P(400$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

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

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

$P(400$

And we can find this probability with this difference:

$P(-1$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(-1$

Part c

For this part we want to find a value a, such that we satisfy this condition:

$P(X>a)=0.8$ (a)

$P(X$ (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.

As we can see on the figure attached the z value that satisfy the condition with 0.2 of the area on the left and 0.8 of the area on the right it's z=-0.842. On this case P(Z<-0.842)=0.2 and P(Z>-0.842)=0.8

If we use condition (b) from previous we have this:

$P(X$

$P(z$

But we know which value of z satisfy the previous equation so then we can do this:

$z=-0.842$

And if we solve for a we got

$a=500 -0.842*100=415.8$

So the value of height that separates the bottom 20% of data from the top 80% is 415.8.

8 0

3 years ago