Help its due in an hour and i cant solve this

The time taken to assemble a laptop computer in a certain plant is a random variable having a normal distribution of 20 hours an

ludmilkaskok [199]

Answer:

a) 40.13% probability that a laptop computer can be assembled at this plant in a period of time of less than 19.5 hours.

b) 34.13% probability that a laptop computer can be assembled at this plant in a period of time between 20 hours and 22 hours.

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

$\mu = 20, \sigma = 2$

a)Less than 19.5 hours?

This is the pvalue of Z when X = 19.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{19.5 - 20}{2}$

$Z = -0.25$

$Z = -0.25$ has a pvalue of 0.4013.

40.13% probability that a laptop computer can be assembled at this plant in a period of time of less than 19.5 hours.

b)Between 20 hours and 22 hours?

This is the pvalue of Z when X = 22 subtracted by the pvalue of Z when X = 20. So

X = 22

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{22 - 20}{2}$

$Z = 1$

$Z = 1$ has a pvalue of 0.8413

X = 20

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{20 - 20}{2}$

$Z = 0$

$Z = 0$ has a pvalue of 0.5

0.8413 - 0.5 = 0.3413

34.13% probability that a laptop computer can be assembled at this plant in a period of time between 20 hours and 22 hours.

4 0

3 years ago

What 2 numbers add to get 2 and multiply to 4

rusak2 [61]

Factor 4
4=1 times 4
2 times 2
they don't add to 2
set up equation
x+y=2
xy=4

first equation, subtract x from both sides
y=2-x
subsitute for y
x(2-x)=4
distribute
2x-x^2=4
add x^2
2x=x^2+4
subtract 2x
0=x^2-2x+4
use quadratic formula which is
if you have ax^2+bx+c=0 then
x= $\frac{ -b+/-\sqrt{b^{2}-4ac} }{2a}$ so

1x^2-2x+4=0
a=1
b=-2
c=4
x= $\frac{ -(-2)+/-\sqrt{(-2)^{2}-4(1)(4)} }{2(1)}$
x= $\frac{ 2+/-\sqrt{4-16} }{2}$
x= $\frac{ 2+/-\sqrt{-12} }{2}$
we have $\sqrt{-12}$ and that doesn't give a real solution
therefor there are no real solutions
but if you want to solve fully
x= $\frac{ 2+/-2\sqrt{-3} }{2}$
i= $\sqrt{-1}$
x= $\frac{ 2+/-2i\sqrt{3} }{2}$
x= $1+/-i\sqrt{3}$
x= $1-i\sqrt{3}$ or x= $1+i\sqrt{3}$ (those are the 2 numbers)

6 0

4 years ago

Dhfnfnsngsdbnchfbmfnbmbmhfnc

finlep [7]

4/32 = x/100
answer: x = 12.5

3 0

3 years ago

A tile factory shipped 342,805 ceramic tile in 2010. In 2011, they shipped 342,805tiles. In which Year did the tile factory ship

Nimfa-mama [501]

It would be = because they shipped the same amount in each year

8 0

3 years ago

Read 2 more answers

6. Identify the recursive formula for the sequence 3, –15, 75, –375, . . .

vlada-n [284]

Answer:

first option

Step-by-step explanation:

There is a common ratio r between consecutive terms in the sequence, that is

r = - 15 ÷ 3 = 75 ÷ - 15 = - 375 ÷ 75 = - 5

The recursive formula allows a term in the sequence to be found by multiplying the previous term by r , thus

f(n) = - 5f(n - 1) if n > 1

with f(1) = 3 ← first term

4 0

3 years ago