Answer:
2.42
Step-by-step explanation:
standard deviation= sqrt(variance)
Variance=E[X2] - E[X]2
E[X] = sum(X)/n=35/9, so E[X]2 = 1225/81
E[X2] =sum(X2)/n = 189/9 = 170/81
Variance= 476/81
Standard deviation = sqrt(476/81) ~2.42
I believe it is C hope this helps
Answer:
The expressions for the payment made to Mary are,
(Monday) 90 = 15m + b
(Tuesday) 62 = 8m + b
where m and b are the fee per student and the base fee, respectively. Solving for m and b, the values are 4 and 30.
The equation that represents Mary's earning is
y = 4x + 30
For 20 students,
y = 4(20) + 30 = 110
For Lisa's earnings,
y = 8x + 15
Substituting 20,
y =8(20) + 15 = 175
Thus, Lisa would earn more than Mary by $65.
(Btw this is not my work, I got it from someone else on brainly and wanted to help lol)
