Answer:
a) Decrease
b) New mean = 78.43
c) Decrease
Step-by-step explanation:
We are given the following in the question:
Total number of students in class = 28
Average of 27 students = 79
Standard Deviation of 27 students = 6.5
New student's score = 63
a) The new student's score will decrease the average.
b) New mean


New mean =

Thus, the new mean is 78.43
c) Since the new mean decreases, standard deviation for new scores will decrease.
This is because the new value is within the usual values i.e. within two standard deviations of the mean. So, this wont cause a lot of variation as this value will be closer to already available data values. Also number of observations (n) in the denominator is increasing. Based on both these points we can conclude that standard deviation will decrease
Formula for Standard Deviation:
where
are data points,
is the mean and n is the number of observations.
Answer:
115° and 245°
Step-by-step explanation:
Given
cos x = - 0.4226
Since cos x < 0 then x is an angle in the second / third quadrants, thus
x = (0.4226) = 65° ← related acute angle , thus
x = 180° - 65° = 115° ← angle in second quadrant
x = 180° + 65° = 245° ← angle in third quadrant
250000
=
13597.781437
t
Let's solve your equation step-by-step.
250000
=
13597.781437
t
Step 1: Flip the equation.
13597.781437
t
=
250000
Step 2: Divide both sides by 13597.781437.
13597.781437
t
13597.781437
=
250000
13597.781437
t
=
18.385352
Answer:
t
=
18.385352
4800/6 = 800
Hope this helps.