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:For this case, the first thing we must do is define variables.
x: amount of time Miguel uses to complete the task.
y: amount of time Maria uses to complete the task.
We write the system of equations:
x + y = 60
y = (1/2) x
Solving the system we have:
x = 40 minutes
y = 20 minutes
Answer:
it take her to wash them by herself about:
y = 20 minutes
Step-by-step explanation:
Answer:
The number of <u>dimes are 100</u> and number of <u>quarters are 140.</u>
Step-by-step explanation:
Let the number of dimes be 'd' and quarters be 'q'.
Given:
The sum of amount is $45.
The total number of coins are 240.
1 dime = $0.10
∴ 'd' dimes = 
1 quarter = $0.25
∴ 'q' quarters = 
Now, as per question:

Multiplying equation (1) by -0.1 and adding the result to equation (2), we get:

Therefore, the number of dimes are 100 and number of quarters are 140.