<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.
To find the surface area of any object, the first step that you must do is find all shapes that are present in the object.
Here we have 2 triangles and 3 rectangles.
Knowing this, simply find the area of each shape.
Since the triangles are the same, one is facing up and the other down, they both would be 15.6 cm^2.
The rectangles would be 54 cm^2. as there are 3 ( 6 x 3 cm) ones.
Add the values up to have the surface area.
It’s 85.2 cm^2.
Answer:
Option A) independent variable – self-affirmations; dependent variable – self-esteem scores
Step-by-step explanation:
We are given the following in the question:
"Wood and colleagues (2009) examined the value of self-affirmation. In a typical study, participants either engaged or did not engage in self-affirmations. Later, their current self-esteem was assessed."
Independent and Dependent Variable:
- Dependent variable is the variable whose value depends on the independent variable.
- Independent variable is the free variable.
For the given scenario, self esteem is assessed based on the fact that participants either engaged or did not engage in self-affirmations.
Thus, the dependent variable is self esteem and the independent variable is engagement in self affirmation.
Thus, the correct answer is
Option A) independent variable – self-affirmations; dependent variable – self-esteem scores
Equation of an ellipse
→having center (0,0) , vertex (
and covertex
and focus
is given by:

As definition of an ellipse is that locus of all the points in a plane such that it's distance from two fixed points called focii remains constant.
Consider two points (a,0) and (-a,0) on Horizontal axis of an ellipse:
Distance from (a,0) to (c,0) is = a-c = 
Distance from (-a,0) to (c,0) is = a + c = 
a -c + a +c
= a + a
= 2 a →(Option A )
That should be the answers