A Biology teacher wants to see if there is any difference in the abilities of students enrolled in biology today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information. Today Five Years Ago 81 85 σ 14.5 8.5 n 81 36 ​ The point estimate for the difference between the means of the two populations is

The point estimate for the difference between the means of the two populations is x1`-x2`= 81-85=-4 where x1` is the mean of the of the first population and x2` is the mean of the second population.

Step-by-step explanation:

The data given is

               Today               Five Years Ago

X`                 81                           85

σ              14.5                        8.5

n                81                          36

The point estimate for the difference between the means of the two populations is x1`-x2`= 81-85=-4 where x1` is the mean of the of the first population and x2` is the mean of the second population.

The test statistics that will be used is

Z= x1-x2/ √σ₁²/ n₁ + σ₂²/n₂

Z=  81- 85/ √14.5² /81 + 8.5² /36

z= -4/√210.25/81+ 72.25/36

z= -4/2.1454

z= -1.8644

spinning a 1, 2, or 3. option d.

step-by-step explanation: when spinning a number graph up to 4, and aiming for any number less than 3, that automatically eliminates the number 4. now you have two numbers to spin on that are less than 3, but the number 3 is included in this question because it's no greater of an number than itself. i hope this you : )

both equations and proportions are better.