Answer:
And we can find this probability using the complement rule and we got:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule and we got:
Answer:
b.
Step-by-step explanation:
The range means the values of y and in this graph, the values of y are 1,2,3 and 4.
Answer:
Step-by-step explanation:
He scored 85%
(17/20)%
85%
Answer:
(a)
,
,
,
,
,
,
.
(b)
,
,
,
,
,
,
,
.
Step-by-step explanation:
In this exercise we only need to recall the formula for C(n,k):

where the symbol
is the factorial and means
.
By convention 0!=1. The most important property of the factorial is
, for example 3!=1*2*3=6.
(a) The explanations to the solutions is just the calculations.
.
(b) The explanations to the solutions is just the calculations.
For all the calculations just recall that 4! =24 and 5!=120.
Answer:
x = 1
y = 30°
Step-by-step explanation:
is RS is ⊥ to TU then TS = US so we can use this equation to find 'x':
20x-3 = 5x+12
15x = 15
x = 1
we also know that RS intersecting with TU creates a 90° angle
if 3y = 90 then y = 30