Answer:
Check the explanation
Step-by-step explanation:
Let
and
be sample means of white and Jesse denotes are two random variables.
Given that both samples are having normally distributed.
Assume
having with mean
and
having mean 
Also we have given the variance is constant
A)
We can test hypothesis as

For this problem
Test statistic is

Where

We have given all information for samples
By calculations we get
s=2.41
T=2.52
Here test statistic is having t-distribution with df=(10+7-2)=15
So p-value is P(t15>2.52)=0.012
Here significance level is 0.05
Since p-value is <0.05 we are rejecting null hypothesis at 95% confidence.
We can conclude that White has significant higher mean than Jesse. This claim we can made at 95% confidence.
Answer:
Distance = 73 m
Step-by-step explanation:
Given that,
The length of a rectangle = 48 m
The width of a rectangle = 55 m
We need to find the diagonal distance. We can use the Pythagoras theorem to find it.

So, the required distance is equal to 73 m.
Answer: (80% , 85%)
Step-by-step explanation:
We know that, confidence interval for population proportion is given by :-
(p-E , p+E)
, where p = sample proportion , E = Margin of error.
Given : Proportion of elementary school teachers who are female = 82%.
The article also states the maximum error of their estimate = 3%.
Then, the 90% confidence interval for the proportion of elementary school teachers who are female will be :
(82%-2% , 82%+3%)
= (80% , 85%)
Hence, the resulting 90% confidence interval for the proportion of elementary school teachers who are female = (80% , 85%)
<span>Last
year, the average math SAT score for students at one school was 475. The
headmaster then introduced a new teaching method hoping to improve scores. This
year, the mean math SAT score for a sample of students was 491. The headmaster
concluded that the new teaching method produces higher SAT scores. The problem
with reporting results this way is voluntary response. The information of how
the teaching method isnot mentioned.</span>