Given that mean=3750 hours and standard deviation is 300:
Then:
<span>a. The probability that a lamp will last for more than 4,000 hours?
P(x>4000)=1-P(x<4000)
but
P(x<4000)=P(z<Z)
where:
z=(x-</span>μ)/σ
z=(4000-3750)/300
z=0.833333
thus
P(x<4000)=P(z<0.8333)=0.7967
thus
P(x>4000)=1-0.7967=0.2033
<span>b.What is the probability that a lamp will last less than 3,000 hours?
P(x<3000)=P(z<Z)
Z=(3000-3750)/300
z=-2.5
thus
P(x<3000)=P(z<-2.5)=0.0062
c. </span><span>.What lifetime should the manufacturer advertise for these lamps in order that only 4% of the lamps will burn out before the advertised lifetime?
the life time will be found as follows:
let the value be x
the value of z corresponding to 0.04 is z=-2.65
thus
using the formula for z-score:
-2.65=(x-3750)/300
solving for x we get:
-750=x-3750
x=-750+3750
x=3000</span>
Answer:
<em>The slope of the line is m=6. </em>
<em>The y-intercept is (0,−24). </em>
<em>The equation of the line in the slope-intercept form is y=6x−24.</em>
Step-by-step explanation:
The slope of the line passing through the two points P=(x1,y1) and Q=(x2,y2) is given by m=y2−y1x2−x1.
We have that x1=2, y1=−12, x2=5, y2=6.
Plug the given values into the formula for the slope: m=(6)−(−12)(5)−(2)=183=6.
Now, the y-intercept is b=y1−m⋅x1 (or b=y2−m⋅x2, the result is the same).
b=−12−(6)⋅(2)=−24.
Finally, the equation of the line can be written in the form y=mx+b.
y=6x−24.
Answer:
The slope of the line is m=6.
The y-intercept is (0,−24).
The equation of the line in the slope-intercept form is y=6x−24.
Answer:
A- 15-5 is the same
Step-by-step explanation:
15 + (3-8)
15 + (-5)
15-5
Answer:
A
Step-by-step explanation:
Hey There!
So these triangles are congruent so segment CD is equal to segment DB
so to find x we use the equation
7x+10=10x+7
now we solve for x
step 1 subtract each side by 7
10-7=3
7-7 cancels out
now we have 7x+3=10x
step 2 subtract each side by 7 x
10x-7x=3x
7x-7x= cancels out
now we have
3x=3
step 3 divide each side by 3
3/3=1
3/3 cancels out
now we have
x=1
Styline menswear ordered short-sleeve shirts for $23 each and long-sleeve shirts for $28.50
short-sleeve shirts for $23
long-sleeve shirts for $28.50
Total cost = $9,862.50
Let x be the number of short - sleeve
and y be the number of long - sleeve
Total shirts = 375
x + y = 375
23x + 28.50y = 9862.50
Now we solve for x
x + y = 375 ( subtract x on both sides)
So y = 375 - x
Now plug in 375 -x for y in second equation
23x + 28.50y = 9862.50
23x + 28.50(375 - x ) = 9862.50
23x + 10687.5 - 28.50x = 9862.50
subtract 10687.5 from both sides
23x - 28.50x = -825
-5.5x = -825 (divide -5.5 on both sides)
x = 150
So number of short-sleeve = 150
