Answer: 0.0775
Step-by-step explanation:
Given : Mean : 
Standard deviation : 
Sample size : 
Since its normal distribution , then the formula to calculate the z-score is given by :-

For x= 28.2 hours

For x= 30 hours

The P- value = 

Hence, the probabiliy that the average time spent stydying for the sampe was between 28.2 and 30 hours = 0.0775
Answer:
Step-by-step explanation:
6
x and y are the packs of organic and inorganic fertilizer, respectively.
pounds of nitrogen added = 2x + 6y = 120
pounds of potassium added = 3x + 2y = 54
eliminate the y terms. subtract the first equation from 3 times the second equation.
9x + 6y = 162
-2x - 6y = -120
------------------
7x = 42
x = 6
y = 18
Answer:
Step-by-step explanation:
is this a test?
Answer:
Both lights would flash together after every 30 seconds.
Step-by-step explanation:
6 = 2 * 3 and 10 = 2 * 5.
LCM (Least Common Multiple) of 6 and 10 = 2 * 3 * 5 = 30.
Therefore, both lights wold flash together after every 30 seconds.