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:
x=3 x = -1
Step-by-step explanation:
f(x) = x^2 − 2x − 3
Set the function equal to zero
0 = x^2 − 2x − 3
Factor
What two numbers multiply to -3 and add to -2
-3 *1 = -3
-3+1 = -2
0 = (x-3)(x+1)
Using the zero product property
x-3 =0 x+1 =0
x=3 x = -1
Answer: There are 8 snake and 3 elephants.
Step-by-step explanation:
Let x= Number of snakes
y= Number of elephants
We know that , snake has no legs elephant has 4 legs.
Then, Total animals = x+y=11 (i)
Total legs = 4y = 12
⇒ y=3 .. (ii)[divide both sides by 4]
Substitute value of y from (ii) in (i) , we get

Hence, there are 8 snake and 3 elephants.
11. 0.03, 3/10,1 1/8,1 5/6,2
B!
Hope this answer can help you!