Answer:
b. The student's scores on the posttest would have a smaller standard deviation.
Step-by-step explanation:
The first test is taken before the material is covered in class so we expect the standard deviation to be high because not everyone's scores would be lying close to the mean. Equal number of students mastered most, some or almost none of the material from reading the textbook based on the pretest result. this means the data is varying, so the standard deviation is large.
Whereas, after the teacher has taught the material and given the homework, they must have understood most of the material. The test they take after teaching as a post test. The results of the post test would have a smaller standard deviation as most of the students would have scored good. Hence, the student's scores on the posttest would have a smaller standard deviation.
Let
x---------> the number
we know that
[9+2x]*4=4x+12
36+8x=4x+12
8x-4x=12-36
4x=-24
x=-24/4
x=-6
the answer is
-6
Answer:
It will take him about 13 houses to sell the 5 candy bars.
Pat has an 18% chance of selling his last candy in the 11th house.
Step-by-step explanation:
Since Pat is required to sell candy bars to raise money for the 6th grade field trip, and there is a 40% chance of him selling a candy bar at each house, and he has to sell 5 candy bars in all, to determine the number of houses it takes and determine the probability he sells his last candy bar at the 11th house, the following calculations must be performed:
5 / 0.40 = X
12.5 = X
So, it will take him about 13 houses to sell the 5 candy bars.
5/11 = X
0.45 = X
0.45 x 0.4 = 0.18
Thus, Pat has an 18% chance of selling his last candy in the 11th house.
Answer: 15%
Step-by-step explanation:
The Percentage decrease will be:
= Decrease in weight / Old weight × 100
= (200 - 170) / 200 × 100
= 30/200 × 100
= 15%
The Percentage decrease is 15%
