Answer:
2.28% probability that a person selected at random will have an IQ of 110 or greater
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
What is the probability that a person selected at random will have an IQ of 110 or greater?
This is 1 subtracted by the pvalue of Z when X = 110. So
has a pvalue of 0.9772
1 - 0.9772 = 0.0228
2.28% probability that a person selected at random will have an IQ of 110 or greater
The answer would be -4.5/5. You would have to plot the number in between -2 and - 1 4/5. Hope this helps!
There are three groups of people: 25 years old and younger, between 25 to 50, and 50 years old and older. Their fractions must equal to 1 because these three together form the whole.
1 = 1/3 + 2/7 + x
where x is the fraction for people ages 25 to 50 years old
x = 8/21
So, the actual number of people ages 25 to 50 years old is:
84(8/21) = 32 people
Answer:
Step-by-step explanation:
We will start by using the quadratic formula.
We will simplify that and get:
So our answers would be:
Answer:
a+305/36
Step-by-step explanation:
Convert
3
1
4
3
1
4
to an improper fraction.
a
+
13
4
+
5
2
9
a
+
13
4
+
5
2
9
Convert
5
2
9
5
2
9
to an improper fraction.
a
+
13
4
+
47
9
a
+
13
4
+
47
9
To write
13
4
13
4
as a fraction with a common denominator, multiply by
9
9
9
9
.
a
+
13
4
⋅
9
9
+
47
9
a
+
13
4
⋅
9
9
+
47
9
To write
47
9
47
9
as a fraction with a common denominator, multiply by
4
4
4
4
.
a
+
13
4
⋅
9
9
+
47
9
⋅
4
4
a
+
13
4
⋅
9
9
+
47
9
⋅
4
4
Write each expression with a common denominator of
36
36
, by multiplying each by an appropriate factor of
1
1
.
a
+
13
⋅
9
36
+
47
⋅
4
36
a
+
13
⋅
9
36
+
47
⋅
4
36
Combine the numerators over the common denominator.
a
+
13
⋅
9
+
47
⋅
4
36
a
+
13
⋅
9
+
47
⋅
4
36
Simplify the numerator.
a
+
305
36
a
+
305
36
