Answer:
31 scientific calculators
54 graphing calculators
Step-by-step explanation:
X = number of $15 calculators
Y = number of $67 calculators
X+Y = 85 then X = 85-Y
15X+67Y = 4083
substitute for X
15(85-Y)+67Y = 4083
1275 - 15Y + 67Y = 4083
reduce
52Y = 2808
Y = 54
X = 31
She practices 5 hours a day.
120/4 = 30 hours per week.
30/6 = 5 hours per day.
A) 2 3/8
Because 2 times 8 gives you 16 then you add 3 which equals to 19.
Hope this helped!
The shape of the distribution, is symmetric, is the best description of statistics about scores.
<h3 /><h3>What is standard deviation ?</h3>
The standard deviation is the positive square root of the variance of this data set. Variance of a data set is the sum of squared differences of the data values from its mean to the total count of data values.
The given data in the problem is;
Mean = 78%
Standard deviation = 4%
Min = 64
Median = 78
Q1 = 72
Q3 = 84
Max = 99
The condition for the symmetric distribution is found as;

From the data we have;

So that ,
.
Hence, the condition of symmetry is followed.
To learn more about the symmetry, refer to the link;l
brainly.com/question/15970176
#SPJ2
Answer: 85 degrees
Step-by-step explanation: 20x+5+24x-1=180
44x+4=180
-4 -4
44x=176
division property of equality x=4
20(4)+5=
80+5= 85 degrees