In a recent year, a sample of grade 8 Washington State public school students taking a mathematics assessment test had a mean score of 281 with a standard deviation of 34.4. Possible test scores could range from 0 to 500. Assume that the scores are normally distributed. Question 9 (2.5 points) If 2000 students are randomly selected, how many would you expect to have a score between 250 and 305?

The  number is   students

Step-by-step explanation:

From the question we are told that

    The population mean is  

     The standard deviation is  

    The sample size is  n = 2000

percentage of the would you expect to have a score between 250 and 305 is mathematically represented as

     

Generally  

             

So  

         

       

From the z table  the value of  

                                         and  

     

     

The  percentage is  

The  number of students that will get this score is

           

           

Given that the relationship between kilometers and fuel is proportional, let the distance in km be k and the fuel be f:
thus:
kα cf
k=cf
where k is the constant of proportionality. Thus:
c=k/f
Pamela drove 99 km and used 9 liters;
∴k=99/9=11 km/liter
therefore distance covered is given by:
k=11f
hence the distance covered with 12 liters of fuel will be:
k=11×12
=132 km