<u>Answer</u>: No, we do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
Step-by-step explanation:
As per given , we have
, since
is two-tailed so , the test is a two tail test.
Since population standard deviation is unknown, so we use t-test.
Critical value (two-tailed) for significance level of 0.01=
For n =50 ,
and s= 4.8
Test statistic : 

Since test statistic value (-1.18) lies in critical interval (-2.609228, 2.609228), it means the null hypothesis is failed to reject.
We do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
Answer:
The diameter is 91.
Step-by-step explanation:
The formula for circumference is 2*pi*radius(you can use circumference = diameter*pi too). Plug 285.74 into it. Divide both sides by 3.14, and you get 2*radius(aka the diameter) = 91
Answer: The height of the new player is 210 cm
Step-by-step explanation: The previous mean of the entire team has been calculated as 200.3
What this means is that, we have a summation of the observed data and a summation of the frequency of data.
The mean was calculated as
Sum FX/Sum F = 200.3
Where Sum FX is 2604 and Sum F is 13
However, our calculation should now read thus,
Sum FX/Sum F = 201 {where 201 is the new mean}
By cross multiplication we now have
Sum FX = Sum F x 201
Remember that a new member has joined the team so our Sum F is now 14 and we can now express it as thus
Sum FX = 14 x 201
Sum FX = 2814
If the summation of the observed data after adding a new team member is now 2814, then the addition to the previous observed data would be
2814 - 2604 = 210
So the height of the new member added to the team is 210 cm.
Answer:
120 deg
Step-by-step explanation:
4.4a-7.3 is equal to
4.4a= 7.3 divide both sides by 4.4
a= 1.66