Answer:
Jaw saw an average of 6 birds each day
Step-by-step explanation:
Given: One day, Jean saw 7 birds. The next day, she saw 11 birds. The next day, she saw no birds.
To find: average number of birds Jean saw each day
Solution:
Average is a central value of a set of terms.
Average of terms
is given by 
Number of birds, Jean saw on day one
= 7
Number of birds, Jean saw on the second one
= 7
Number of birds, Jean saw on the third one
= 7
So,
average number of birds Jean saw each day = 
Therefore,
Jaw saw an average of 6 birds each day
Answer: a) z=1.43
b) 0.1528
Step-by-step explanation:
The given set of hypothesis :


Since the alternative hypothesis
is two-tailed , so we perform two-tailed test.
Also, it is given that : A random sample of n=76 Americans found 28 with brown eyes.
Sample proportion: 
a) The z-statistic would be :-


b) P-value for two-tailed test = 2P(Z>|z|)= 2P(z>|-1.43|)
=2P(z>1.43)
=2(1-P(z≤1.43)
=2-2P(z≤1.43)
= 2-2(0.9236)[Using standard z-table]
= 2-1.8472=0.1528
Hence, the P-value of the test= 0.1528
Sure : Do 3,000 x 6 and you will see what you get and that’s the answer
15x=180
x=12
hope this helps
Answer:
Amount invested at 7% = 16000
Amount invested at 9% = 12000
Step-by-step explanation:
Let x be the amount invested at 7% and y be the amount invested at 9%.
Since the total amount invested is $28000, therefore, we can set up the first equation as:

Secondly, we are give that sum of two investments is $2200. Therefore, we can write the second equation as:

Now we need to solve these two equations to get the values of x and y.
First of all, we multiply the second equation with 100 in order to get rid of decimal values.

Let us use substitution method here. First of all we will solve for y from first equation and plug that into second equation.


Therefore, amount invested at 7% is $16000 and amount invested at 9% is 28000-16000=$12000.