13. Listed below are the amounts of time (in months) that the employees of a restaurant have been working at the restaurant. Find the standard deviation of the data set, rounding to one more decimal place than is present in the data. 2 3 5 13 22 35 60 86 101 122

a. 44.5 months

b.42.2 months

c. 45.8 months

d. 43.3 months

Option B) 42.2 months

Step-by-step explanation:

We are given the following data of the amount of time in months.

2, 3, 5, 13, 22, 35, 60, 86, 101, 122

We have to find the standard deviation.

Formula:

where are data points, is the mean and n is the number of observations.  

Sum of squares of differences =

1840.41 + 1755.61 + 1592.01 + 1017.61 + 524.41 + 98.01 + 228.01 + 1689.21 + 3147.21+ 5944.41 = 17836.9

Thus, the standard deviation of given data set is 42.2 months.

Option B) 42.2 months

94

step-by-step explanation:

average the numbers and use a variable to figure out the minimum to get a 90.

(79+94+91+92+x)/5=90

x = 94

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -