Answer:



Step-by-step explanation:
Given

Solving (a): Point estimate of difference of mean
This is calculated as: 


Solving (b): 90% confidence interval
We have:


Confidence level is: 



Calculate 


The z score is:

The endpoints of the confidence level is:






Split


Hence, the 90% confidence interval is:

Solving (c): 95% confidence interval
We have:


Confidence level is: 



Calculate 


The z score is:

The endpoints of the confidence level is:






Split


Hence, the 95% confidence interval is:

I thought it would be c but try b or a
The answer is y = 2x + 3.
x - Kay's age
y - Jane's age
m - Mary's age
<span>Jane is 3 years older than Mary: y = m + 3
</span><span>Mary is twice as old as Kay: m = 2x
</span><span>
y = m + 3
m = 2x
Substitute m in the first equation:
y = 2x + 3
</span>
Answer:
Test statistic = 2
P-value = 0.0227
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = $98
Sample mean,
= $100
Sample size, n = 100
Population standard deviation, σ = $10
First, we design the null and the alternate hypothesis
Formula:
Putting all the values, we have
Now, we can calculate the p-value from the normal table
P-value = 0.0227