Four times the sum of a number and 20 is at most -17
1 answer:
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Answer:
The standard deviation of the given data is 11.34.
Step-by-step explanation:
We have to find the standard deviation for the given data;
Grade on No. of students
test (X) with that score (f)
50 1 50 1073.218 1073.2176
57 2 114 663.578 1327.1552
60 4 240 518.018 2072.0704
65 3 195 315.418 946.2528
72 3 216 115.778 347.3328
75 12 900 60.218 722.6112
77 10 770 33.178 331.776
81 6 486 3.098 18.5856
83 6 498 0.058 0.3456
88 9 792 27.458 247.1184
90 12 1080 52.418 629.0112
92 12 1104 85.378 1024.5312
95 2 190 149.818 299.6352
99 4 396 263.738 1054.9504
100 <u> 5 </u> <u> 500 </u> 297.218 <u> 1486.088 </u>
Total <u> 91 </u> <u> 7531 </u> <u> 11580.68 </u>
Firstly, the mean of the above data is given by;
Mean, =
= = 82.76
Now, the standard deviation of the data is given by;
Standard deviation, S.D. =
=
= 11.34
Hence, the standard deviation of the given data is 11.34.
Answer:
The discriminant is -7
Step-by-step explanation:
The discriminant of a quadratic function/equation(ax^2+bx+c = 0) is calculated as:
Here
b is the co-efficient of x
a is the co-efficient of x^2
and c is the constant
Given equation is:
Here
a = -2
b = 5
c = -4
Putting the values in the formula for discriminant
As the discriminant is negative, the equation has no real solution.
Hence,
The discriminant is -7