Help on question on math precalculus Question states-Which interval(s) is the function decreasing?Group of answer choicesBetween
1.5 and 4.5Between -3 and -1.5Between 7 and 9Between -1.5 and 4.5
1 answer:
We have a function of which we only know the graph.
We have to find in which intervals the function is decreasing.
We know that a function is decreasing in some interval when, for any xb > xa in the interval, we have f(xa) < f(xb).
This means that when x increases, f(x) decreases.
We can see this intervals in the graph as:
We assume each division represents one unit of x. Between divisions, we can only approximate the values.
Then, we identify all the segments in the graph where f(x) has a negative slope, meaning it is decreasing.
We have the segments: [-3, -1.5), (1,5, 4.5) and (7,9].
Answer:
The right options are:
Between 1.5 and 4.5
Between -3 and -1.5
Between 7 and 9
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Answer:
8x² +36x -27=0
Step-by-step explanation:
2x²= 6x +3
Let's rewrite the equation into the form of ax²+bx+c= 0.
2x² -6x -3=0
Thus, a= 2
b= -6
c= -3
Sum of roots=
Since your roots are p and q, sum of roots= p +q
p +q=
p +q= 6 ÷2
p +q= 3
Product of roots=
pq=
<u>Quadratic equations</u><u>:</u>
x² -(sum of roots)x +(product of roots)= 0
Thus, we have to find the sum and the product of the new roots, p²q and pq².
p +q= 3
pq= -3/2
Product of new roots
= (p²q)(pq²)
= p³q³
= (pq)³
sum of new roots
= p²q +pq²
= pq(p +q)
= (-3/2)(3)
= -9/2
Thus, the quadratic equation with roots p²q and pq² is
x² -(-9/2)x -27/8 = 0
Multiply by 8 throughout:
Answer:
The p-value of the test is 0.0139 < 0.05, which means that these data indicates that the population proportion of voter turnout in Colorado is higher than that in California.
Step-by-step explanation:
Before testing the hypothesis, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean and standard deviation
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
California:
Sample of 296 voters, 146 voted. This means that:
Colorado:
Sample of 215 voters, 127 voted. This means that:
Test if the population proportion of voter turnout in Colorado is higher than that in California:
At the null hypothesis, we test if it is not higher, that is, the subtraction of the proportions is at most 0. So
At the alternative hypothesis, we test if it is higher, that is, the subtraction of the proportions is greater than 0. So
The test statistic is:
In which X is the sample mean, is the value tested at the null hypothesis, and s is the standard error.
0 is tested at the null hypothesis:
This means that
From the two samples:
Value of the test statistic:
P-value of the test and decision:
The p-value of the test is the probability of finding a difference above 0.0975, which is 1 subtracted by the p-value of z = 2.2.
Looking at the z-table, z = 2.2 has a p-value of 0.9861.
1 - 0.9861 = 0.0139.
The p-value of the test is 0.0139 < 0.05, which means that these data indicates that the population proportion of voter turnout in Colorado is higher than that in California.