Answer:
31465 ways
Step-by-step explanation:
Given data
Let us apply the combination formula
nCr = n! / r! * (n - r)!
n= 31
r= 4
substitute
= 31!/4!(31-4)!
= 31!/4!(27)!
= 31*30*29*28*27!/ 4!(27)!
= 31*30*29*28/4!
=31*30*29*28/4*3*2*1
=755160/24
=31465 ways
Hence there are 31465 possible ways to rank it
(8c)^2+7c
(8c)^2=64c^2
so that..
64c^2+7c
factor out c
c(64c+7)
Answer:
8
Step-by-step explanation:
hope it will help good luck
first speed --- x mph
return speed -- x+16 mph
6/x + 6/(x+16) = 1
times each term by x(x+16)
6(x+16) + 6x = x(x+16)
x^2 + 4x - 96 = 0
(x-8)(x+12) = 0
x = 8 or x is a negative
her first speed was 8 mph
her return speed was 24 mph
check:
6/8 + 6/24 = 1 , that's good!
Answer:
Reject H0
Step-by-step explanation:
Given :
H0: The frequencies are equal. H1: The frequencies are not equal
Category f0 A 10 B 30 C 30 D 10
Total f0 = (10 + 30 + 30 + 10) = 80
Expected frequency is the same for all categories :
Expected frequency = 1/4 * 80 = 20
χ² = Σ(observed - Expected)² / Expected
χ² = (10-20)^2 / 20 + (30-20)^2 /20 + (30-20)^2 / 20 + (10-20)^2 / 20
χ² = (5 + 5 + 5 + 5) = 20
Pvalue = 0.00017
Pvalue < α
