Standard Deviation (50 points)
Dr. Cwetna recorded all of the grades on a unit test on the chart below.

1. What is the mean and standard deviation of the distribution of individual grades? (30
points)
x=

o=

2. In your own words, explain HOW to find the standard deviation of this data set. (20
points)

3. What does the standard deviation tell you about this data? (20 points)

4. Identify the following and label the dot-plot above (3 points each)
u+-1o= and

u+-20= and

u+-3o= and

Find the percentage of test scores within each range listed above.
5. (4 points) Does the data indicate a normal distribution?

6. (8 points) Explain why or why not?

solution:

we have to construct

∠m nt ≅ ∠p qr

the steps to draw this construction are

step 1: use a compass to draw an arc from point q which intersects the side pq at point a and the side qr at point b.

step 2: draw a segment nt and use the same width of the compass to draw an arc from point n which intersects the segment nt at a point x.

step 3:

step 4: join points n and y using a straightedge.

step 3:

option (d).maintaining the same width of the compass as ab, draw an arc from point x such that it intersects the arc drawn from n in a point y.

to draw   congruent angles , 1. width of compasses while drawing two angles should be same i.e from point at which angle has to be drawn, 2.the distance between the two points where the compass intersects the two sides should be same while drawing any two congruent angles.

(0.2)+(-8)=0.3+-3+0.3m is the equation i guess? ?

step-by-step explanation: