Answer:
Step-by-step explanation:
given that certain tubes manufactured by a company have a mean lifetime of 800 hours and a standard deviation of 60 hours.
Sample size n =16
Std error of sample mean = 
x bar follows N(800, 15)
the probability that a random sample of 16 tubes taken from the group will have a mean lifetime
(a) between 790 and 810 hours,
=
(b) less than 785 hours

, (c) more than 820 hours,

(d) between 770 and 830 hours
=
Answer:
No solutions
Step-by-step explanation:
3x+4y=-4
15x+20y=-22
——————————
-5(3x+4y)=-5(-4) multiply 1st equation by -5 so you can eliminate the variables
-15x-20y=20. Modified 1st equation
15x+20y=-22. 2nd equation
0+0=-2. Added two equations together
since 0 does not equal -2, there is no solution.
Just do 6 x 0.2 to reverse the division
So the answer is 1.2
I think
Answer:

Step-by-step explanation:
Surface area of cylinder = 2πr(h + r)
Volume of cylinder = πr²h
Given that S.A = Volume of the cylinder, therefore, we have:
2πr(h + r) = πr²h
Radius (r) is given as 2.5 cm
height (h) = x cm
Input the values and solve for x
2πr(h + r) = πr²h
2πr(h + r) = πr(rh)
2(h + r) = rh (πr cancels πr)


Subtract 2x from both sides


Divide both sides by 0.5



If Myesha found 6 nickels and 12 quarters under her cushion, this means that she has a total of 18 coins.
<h3>What is an
equation?</h3>
An equation is an expression used to show the relationship between two or more variables and numbers.
Let x represent the number of nickels and y represent the number of quarters. There are 2 cups in 1 pint. Hence:
If she has 6 nickels and 12 quarters:
Number of coins = 12 + 6 = 18
If she has x nickels and y quarters:
Number of coins = x + y
If Myesha has 6 nickels and 12 quarters, this means that she has 18 coins.
Find out more on equation at: brainly.com/question/2972832