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3 years ago

I Will give you 5 stars and brainlisted

Mathematics

1 answer:

Jet001 [13]3 years ago

8 0

Answer:

B) Rotation

Step-by-step explanation:

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A car increased price by 3/4. after the increase it was priced at £84 what was the original price???

olga55 [171]

Answer: I think this is how we do it but i am not sure the answer is 48

Step-by-step explanation:

if the price increase by 3/4 then that mean it total will be 7/4 as 4/4 is it original price add so 7/4=84/x 84x4 is 336 336 divide by 7 is 48 to check 48 x 7/4 or 48 x 3/4 and add 48 if u math is correct than u should get 84

6 0

2 years ago

John jogged 4 1/2 miles. Susan jogged 1/4 of the miles that John jogged. How many miles did Susan jog?

Kobotan [32]

Answer:

Susan jogged 1 1/8 miles

Step-by-step explanation:

4 1/2= 18/4. 18/4 ÷ 1/4= 1.125= 1 1/8

6 0

3 years ago

4. A random variable X has a mean of 10 and a standard deviation of 3. If 2 is added to each value of X, what will the new mean

Ede4ka [16]

Adding 2 to each value of the random variable $X$ makes a new random variable $X+2$ . Its mean would be

$E[X+2]=E[X]+E[2]=E[X]+2$

since expectation is linear, and the expected value of a constant is that constant. $E[X]$ is the mean of $X$ , so the new mean would be

$E[X+2]=10+2=12$

The variance of a random variable $X$ is

$V[X]=E[X^2]-E[X]^2$

so the variance of $X+2$ would be

$V[X+2]=E[(X+2)^2]-E[X+2]^2$

We already know $E[X+2]=12$ , so simplifying above, we get

$V[X+2]=E[X^2+4X+4]-12^2$

$V[X+2]=E[X^2]+4E[X]+4-12^2$

$V[X+2]=(V[X]+E[X]^2)+4E[X]-140$

Standard deviation is the square root of variance, so $V[X]=3^2=9$ .

$\implies V[X+2]=(9+10^2)+4(10)-140=9$

so the standard deviation remains unchanged at 3.

NB: More generally, the variance of $aX+b$ for $a,b\in\mathbb R$ is

$V[aX+b]=a^2V[X]+b^2V[1]$

but the variance of a constant is 0. In this case, $a=1$ , so we're left with $V[X+2]=V[X]$ , as expected.

5 0

3 years ago

Seth traveled one mile in 57.1 seconds. About how fast does Seth travel in miles per hour?

ZanzabumX [31]

Since we need to convert “miles per second” to “miles per hour,” we first need to find out how many seconds there are in a hour.
We know that there are 60 seconds in a minute, and if we wanted to do an hour we would have to do 60 * 60 which is 3600 seconds, therefore,
1 mi/57.1 sec = (1 mi/ 57.1 sec)(3600 sec/1 hour)

= (3600/57.1) mi/hours

 = 63.047 mi/hours

5 0

2 years ago

James Batches of brownie

oksano4ka [1.4K]

Answer:

Step-by-step explanation:

4 0

2 years ago