Answer:

Step-by-step explanation:
The missing parameters are:
--- population
--- population mean
-- population standard deviation
Required

First, calculate the sample standard deviation




Next, calculate the sample mean 

So:

So, we have:



Calculate the z score




So, we have:

From the z table

So:

Answer:
2x + 3y = 6
Step-by-step explanation:
2x + 3y = 6
-2x. -2x
3y/3 = -2x + 6/3
Y = -2/3x + 2
Answer:
Option D
Step-by-step explanation:
We have to find the value of the composite function (h o k)(2).
Since, (h o k)(x) = h[k(x)]
(h o k)(2) = h[k(2)]
From the picture attached,
At x = 2
k(2) = (-2)
Therefore, h[k(2)] = h(-2)
Since, h(x) = 
Therefore, h(-2) = 
= -3
(h o k)(2) = -3 is the answer.
Option (D) is the correct option.
Answer:
66 ≤ f ≤100
Explanation
Mean= ( Σ x ) / n
Mean= sum of scores/ number of subject she took
Now, she already too 3 subject which sum is 85+83+86=254
Now we need to know range of score for her to have (grade) a mark between 80 and 89
Now let take the lower limit mean=80
The lowest score she can get is
Mean = ( Σx) / n
80=(85+83+86+f)/4
80×4= 254+f
Therefore, f= 320-254=66
Therefore the minimum score she can have to have a B is 66.
Then, let take the upper limit mean 89. i.e the maximum she can have so that she don't have an A grade.
Mean = ( Σx) / n
89=( 83+85+86+f)/4
89×4= 254+f
f= 356-254
f=102.
Therefore this shows that she cannot have an A grade in the exam. The maximum score for the exam is 100.
There the range of score is 66 ≤ f ≤100 to have a B grade
66 ≤ f ≤100 answer
Since she cannot score 102 in the examination.
D, because tutoring and receptionist is UPTO 20 hours and the money is AT LEAST 200