If our random variable of interest for this case is X="the number of teenagers between 12-17 with smartphone" we can model the variable with this distribution:

$X \sim Binom(n=234, p=0.75)$

And the mean for this case would be:

$E(X) =np = 234*0.75= 175.5$

And the standard deviation would be given by:

$\sigma =\sqrt{np(1-p)}= \sqrt{234*0.75*(1-0.75)}= 6.624$

Step-by-step explanation:

If our random variable of interest for this case is X="the number of teenagers between 12-17 with smartphone" we can model the variable with this distribution:

$X \sim Binom(n=234, p=0.75)$

And the mean for this case would be:

$E(X) =np = 234*0.75= 175.5$

And the standard deviation would be given by:

$\sigma =\sqrt{np(1-p)}= \sqrt{234*0.75*(1-0.75)}= 6.624$

3 0

3 years ago

HELP NEEDED!!! WILL GIVE 5 STARS!

Jlenok [28]

270=2b + a
420=2a + 3c (you have to use trial and error for this)

B = 120
A = 30
C = 120

Just to check
270 = (2x120) + 30
420 = (2x30) + (3x120)

3 0

3 years ago

2=1/4 4+ b how do I find the y intercept?

Ronch [10]

Answer:

you intercept 2 with the 46721

Step-by-step explanation:

2=64=1/4/5_=24

3 0

3 years ago

Write the equation of the line that passes through the points (2 , -1) and has a slope of - 3

svetlana [45]

Answer:

y=-3x+5

Step-by-step explanation:

y=mx+b

m=slope or gradient (=-3)

y=-3x+b

Add your points

(2, -1)

-1=(-3 x 2)+b

-1= -6+b

-1+6=b

b=5

y=-3x+5

5 0

3 years ago

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