The mean of this sequence of five numbers: 2, N, N+2, 11, 14 is 7.8

[michelleabellan]

1. The mean of this sequence of five numbers: 2, N, N+2, 11, 14 is 7.8

. . .a. What are the two unknown quantities?
. . .b. What is the median of this sequence?

2. Look at each of these sequences of numbers and write down what you think are the next two numbers in each sequence:

. . .a. 1, 2, 4, 8, 16
. . .b. 1, 2, 4, 7, 11
. . .c. 3, 5, 7, 9, 11

3. Looking carefully at this sequence, what you think might be the 53^rd number in the list? (…do not write them all out!)

. . .1, 3, 6, 10, 15

4. Why do you think this sequence may be called “triangular numbers”?

5. What are the prime factors of the following?

. . .a. 2310
. . .b. 5616
. . .c. 146523

 

[JeffM]

This is NOT an answers site. As its name says, it is a HELP site.

We cannot help you if you tell us nothing about what you are studying, what ideas you have about solving the problem, or what work you have done.

Furthermore, it is very confusing to post more than one problem in a single thread.

With respect to your first problem, if the mean of a numbers is b, what is the sum of those numbers?

 

[JeffM]

With respect to the third problem, what is a prime number? How might you determine whether a number is prime or not?

 

[HallsofIvy]

The mean of this sequence of five numbers: 2, N, N+2, 11, 14 is 7.8
What are the two unknown quantities? What is the median of this sequence?

Do you understand what the words "mean" and "median" mean here? The mean of five numbers is their sum divided by 5. What is the sum 2+ N+ (N+2)+ 11+ 14? (It will be an expression that depends upon N.) Divide by 5 and set that equal to 7.8. Solve that for N so that you can determine what N and N+ 2 are. The "median" of a list of numbers is the "middle number" when they are increasing order.