Answer:
169
Step-by-step explanation:
You need to use a Z-table for this.
There are different tables, in this table i searched for the probability of 97% because that equivalent to the top 3%.
for 0.97, Z = 1.88
The formula of Z is:

Solving x:

Answer:
mean=86+72+16+42+16+55+16+12+91+55/2
mean=230.5
mode=16-unimodal
median the middle value but in the first arrange in ascending order.
12,16,42,55,72,86 and 91
median=55
hope it helps!
4(x + 15) > = 120
4x + 60 > = 120
4x > = 120 - 60
4x > = 60
x > = 60/4
x > = 15...........so ur answer is 15 or more
Answer: Alvin = 42 yrs , Elga = 21 yrs
Step-by-step explanation:
Let Elga's age be x , and Alvin's age be y ,since Alvin is two times Elga's age , then
Alvin's age = 2x , that is
y = 2x ............... equation 1
The sum of their ages is 63 implies
x + y = 63 .............. equation 2
Solving the resulting linear equations by substitution method.
Substitute equation 1 into equation 2 , we have
x + 2x = 63
3x = 63
x = 63/3
x = 21
Therefore : Elga is 21 years old , then Alvin will be 21 x 2, which will be 42