Answer:
The call lasted 13 minutes
Step-by-step explanation:
In this question, we are told to find the number of minutes a call lasted.
The initial amount on the card is $30 and after making a phone call just once, the balance went down to $28.83
What was used would be 30 - 28.83 = $1.17 or simply 117 cents
Now these long calls come at a cost of 9 cents per minute and we have a total of 117 cents here; the number of minutes is thus 117/9 = 13
This means Kala spent 13 minutes on the call
Hello : let : y = f(x) so : y' = f'(x)
calculate : f'(x) and : f'(-1) given f(-1) = 2
by derivate : <span>4x3+2y2−11=4xy−x
12x² +4yy' = 4y +4xy' - 1
4yy' - 4xy' = - 12x² +4y -1
y' ( 4y - 4x) = 4y -12x² -1 ...(*)
if x = -1 y = 2 subsct in : (*)
y' (4(2)-4(-1)) = 4(2)-12(-1)² - 1
2y' = - 9
y' = - 9/2 = f'(- 1) ( the slope of the tangent )
</span>of the tangent line to the curve <span>at the point (−1,2) is :
y - 2 = (-9/2)(x +1)</span>
50 > = 15x....divide both sides by 15
50/15 > = x
10/3 > = x or x < = 10/3
so the correct solution set is : { x | x < = 10/3}...its the 2nd one
Answer:
0.2207
Step-by-step explanation:
Here, we want to find the probability that the sample mean is greater than 25.
What we use here is the z-scores statistic
Mathematically;
z-score = (x-mean)/SD/√n
From the question;
x = 65, mean = 63, SD = 13 and n = 25
Plugging these values in the z-score equation, we have
Z-score = (65-63)/13/√25 = 2/13/5 = 0.77
So the probability we want to calculate is ;
P(z > 0.77)
This can be obtained from the standard normal distribution table
Thus;
P(z > 0.77) = 0.22065 which is 0.2207 to 4 d.p
You do 25×.52= 13 then you add 13 to 25, so its 38.
or 25×1.52= 38
