a group of 3 numbers has an average of 17. the first two numbers are 12 and 19. what is the third number? a. 17 b. 19 c. 20 d. 23 e. 30

c. 20

Step-by-step explanation:

The average of 3 numbers is the sum of the three numbers divided by 3.

Let the unknown number be x.

(12 + 19 + x)/3 = 17

Multiply both sides by 3.

12 + 19 + x = 51

Add 12 and 19.

31 + x = 51

Subtract 31 from both sides.

x = 20

c. 20

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;

sas (side angle side)

aa(angle angle)

sss(side side side)

sas you have to find two sides with an angle in between

aa you find two angles because it will always add up to 180

sss find all sides

step-by-step explanation: