Answer:
Step-by-step explanation:
Since the length of time taken on the SAT for a group of students is normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - u)/s
Where
x = length of time
u = mean time
s = standard deviation
From the information given,
u = 2.5 hours
s = 0.25 hours
We want to find the probability that the sample mean is between two hours and three hours.. It is expressed as
P(2 lesser than or equal to x lesser than or equal to 3)
For x = 2,
z = (2 - 2.5)/0.25 = - 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.02275
For x = 3,
z = (3 - 2.5)/0.25 = 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.97725
P(2 lesser than or equal to x lesser than or equal to 3)
= 0.97725 - 0.02275 = 0.9545
Answer:
Step-by-step explanation:
After every Half life , Half of the mass is left.
After 1st Half life = 100 g / 2 = 50 g
After 2nd Half life = 50 / 2 = 25 g
After 3rd Half life = 25 / 2 = 12.5 g
After 4th Half life = 12.5 / 2 = 6.25 g
![\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Crule%5B225%5D%7B225%7D%7B2%7D)
Hope this helped!
<h3>
~AH1807</h3>
The answer is B. If you take the even root of a positive number, you'll get two solutions, a positive and a negative
Mean: 10.5
Median: 10.5
Range: 5
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<u></u>
To find the mean you order the numbers then add then divide.
<u>Add</u>
8+9+10+10+10+11+11+11+12+13=105
<u>Divide</u>
105÷10=10.5
Mean = 10.5
--------------------------------------------
<u></u>
Finding the median essentially involves finding the value in a data sample that has a physical location between the rest of the numbers.
Find the middle number. Put your left finger on 8 and your right finger on 13. Move your left finger to the right to 10 and move your right finger to 11.
the middle number is 10.5 so therefore it is the median.
--------------------------------------------
<u></u>
To find the range you subtract the biggest number to the smallest number.
<u>Subtract</u>
13-8=5
Therefore 5 is the range
Answer: C
Step-by-step explanation:
x = 2
- 6
x + 6 = 2
((x+6)/2 = )^2
(x+6/2)^2 = y+2
y = (x+6/2)^2 -2
y= 1/4x^2 +3x +7
