Hello there! Using the rules of addition, we can identify that when adding a positive to a negative number, the result shifts toward the positive side but takes the sign of the greater number. It will be demonstrated in this problem to simplify how problems like this are solved:
Step 1: Rewrite the problem
-14 + 7 = ?
Step 2: Since we’re adding 7 to a negative number, that means the negative number decreases by the quantity it’s being added by.
This means we would have to really subtract 7 from 14 to get 7.
Step 3: Keep the sign of the greater number
Since 14 is greater than 7, we will keep the negative sign in accordance.
Step 4: Simplify
-14 + 7 = -7
Using the rules of addition, we will find that -14 + 7 = -7. If you need additional help, let me know and I will gladly assist you.
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:
9a-65
Step-by-step explanation:
simply write 9a+(add the remaining numbers all together)
Answer: simplified ratio would be 3:2
Step-by-step explanation: the ratio would be 12:8
Answer:
$337.50
Step-by-step explanation:
$12.50(16) = $200
$5.50(25) = $137.50
Add the totals up:
$200 + 137.50 = $337.50
Ryan's revenue for last month was $337.50 :)
