Answer:
Step-by-step explanation:
The mean SAT score is
, we are going to call it \mu since it's the "true" mean
The standard deviation (we are going to call it
) is

Next they draw a random sample of n=70 students, and they got a mean score (denoted by
) of 
The test then boils down to the question if the score of 613 obtained by the students in the sample is statistically bigger that the "true" mean of 600.
- So the Null Hypothesis 
- The alternative would be then the opposite 
The test statistic for this type of test takes the form

and this test statistic follows a normal distribution. This last part is quite important because it will tell us where to look for the critical value. The problem ask for a 0.05 significance level. Looking at the normal distribution table, the critical value that leaves .05% in the upper tail is 1.645.
With this we can then replace the values in the test statistic and compare it to the critical value of 1.645.

<h3>since 2.266>1.645 we can reject the null hypothesis.</h3>
Answer:
?=1O or 15
Step-by-step explanation:
1/4 + 1/4 = 1/2
I got 1/2 because if you add 1/4 and 1/4 you'd get 2/4, and when you simplify 2/4 you'd get 1/2.
6+5=11+5=16+5=21
3+6=9+6=15+6=21
It will take Marco and Sophie 3 hours to get the same amount of money. The amount of money they will have will be $21.