Answer:
Step-by-step explanation:
This is a question on hypothesis testing.
Population mean based on 30 year average for July was 90 with
a std deviation of 2.1
Sample of 5 shows average 93.5
To check whether sample average = population average
H0: x bar =90
Ha: x bar not equal 90(Two tailed test)
Test statistic = 
=3.73
Since this lies outside the range (-1.96, 1.96) we reject null hypothesis
Hence we cannot say sample mean equals 90
Answer:
60% x 25
55 % x 25
10 in english
25 is total and rest will be math
so 25-10 = 15
15 students failed math
There is 33 students in the class
Answer:
3 * 10^-3
Step-by-step explanation:
It is to the negative third power because the decimal needs to move in front of the 3.
Answer:
x=-1539/445, y=1724/445. (-1539/445, 1724/445).
Step-by-step explanation:
y=9x+35
y=-8/9x+4/5
-------------------
9x+35=-8/9x+4/5
9x-(-8/9x)=4/5-35
9x+8/9x=4/5-175/5
81/9x+8/9x=-171/5
89/9x=-171/5
x=(-171/5)/(89/9)
x=(-171/5)(9/89)
x=-1539/445
y=9(-1539/445)+35
y=1724/445
