Do phone surveys provide adequate coverage of households with respect to one particular parameter? The parameter is the proportion of households without children. If telephone surveys provide adequate coverage of households, then p , the proportion of households without children in the set of all future samples reached by phone, must be equal to the proportion of households without children in the population of all households. Suppose that Thomas, a market analyst, contacts a simple random sample of 300 households as part of a national telephone survey. Of the households contacted, 129 households, or 43 %, have no children and 57 % have at least one child. The most recent census indicates that 48 % of all households have no children and 52 % have at least one child.
Answers
Complete Question
The complete question is shown on the first uploaded image
Answer:
Based on the result of his test , Thomas should fail to reject null hypothesis at a significance level of 0.01. Thomas sufficient evidence to conclude that the proportion of households without children in the set of all future samples reached by phone is not equal to the proportion of households without children in the population of all households.
Step-by-step explanation:
From the question we see that the p-value is greater than the level of significance (0.01 )so we fail to reject the null hypothesis.
This means that Thomas has sufficient evidence to conclude that the proportion of households without children in the set of all future samples reached by phone is not equal to the proportion of households without children in the population of all households.
Related Questions
A new soft drink is being market tested. A sample of 400 individuals participated in the taste test and 80 indicated they like the taste. At 95% confidence, test to determine if at least 22% of the population will like the new soft drink.
Required:
Determine the p-value.
Answers
Answer: p-value of the test = 0.167
Step-by-step explanation:
Given that,
sample size n = 400
sample success X = 80
confidence = 95%
significance level = 1 - (95/100) = 0.05
This is the left tailed test .
The null and alternative hypothesis is
H₀ : p = 0.22
Hₐ : p < 0.22
P = x/n = 80/400 = 0.2
Standard deviation of proportion α = √{ (p ( 1 - p ) / n }
α = √ { ( 0.22 ( 1 - 0.22 ) / 400 }
α = √ { 0.1716 / 400 }
α = √0.000429
α = 0.0207
Test statistic
z = (p - p₀) / α
z = ( 0.2 - 0.22 ) / 0.0207
z = - 0.02 / 0.0207
z = - 0.9661
fail to reject null hypothesis.
P-value Approach
P-value = 0.167
As P-value >= 0.05, fail to reject null hypothesis.
Since test is left tailed so p-value of the test is 0.167. Since p-value is greater than 0.05 so we fail to reject the null hypothesis.
A circle has a radius of 7 inches. What is the area of the circle?
A. 21.98 in^2
B. 43.96 in^2
C. 153.86 in^2
D. 615.44 in^2
Please include ALL work! <3
Answers
Answer:
C. 153.86 in^2[tex]area = \pi {r}^{2} \\ r = 7 \\ a = \frac{22}{7} \times {7}^{2} [/tex]
[tex]a = \frac{22}{7} \times 49 \\ a = 22 \times 7 = 154 {cm}^{2} [/tex]
Step-by-step explanation:
[tex]area = \pi {r}^{2} \\ a \: = 3.14 \times {7}^{2} \\ a \: = 3.14 \times 49 = 153.86 {cm}^{2} [/tex]
Answer:
C. 153.86 in^2
Step-by-step explanation:
The area of a circle can be found using the following formula.
[tex]a=\pi r^2[/tex]
where r is the radius.
We know the radius is 7 inches. Therefore, we can substitute 7 in for r.
[tex]r= 7 in[/tex]
[tex]a=\pi (7 in)^2[/tex]
Evaluate the exponent.
(7 in)^2= 7 in * 7 in= 49 in^2
[tex]a= \pi * 49 in^2[/tex]
Let's use 3.14 for pi.
[tex]a= 3.14 * 49 in^2[/tex]
Multiply 3.14 and 49
3.14 * 49=153.86
[tex]a= 153.86 in^2[/tex]
The area of the circle is 153.86 square inches. Therefore, C is the correct answer.
The lengths of pregnancies in a small rural village are normally distributed with a mean of 265 days and a standard deviation of 14 days. In what range would we expect to find the middle 50% of most lengths of pregnancies
Answers
Answer:
the middle 50% of most lengths of pregnancies ranges between 255.62 days and 274.38 days
Step-by-step explanation:
Given that :
Mean = 265
standard deviation = 14
The formula for calculating the z score is [tex]z = \dfrac{x -\mu}{\sigma}[/tex]
x = μ + σz
At middle of 50% i.e 0.50
The critical value for [tex]z_{\alpha/2} = z_{0.50/2}[/tex]
From standard normal table
[tex]z_{0.25}=[/tex] + 0.67 or -0.67
So; when z = -0.67
x = μ + σz
x = 265 + 14(-0.67)
x = 265 -9.38
x = 255.62
when z = +0.67
x = μ + σz
x = 265 + 14 (0.67)
x = 265 + 9.38
x = 274.38
the middle 50% of most lengths of pregnancies ranges between 255.62 days and 274.38 days
A controversial bill is being debated in the state legislature. Representative Williams wants to estimate within 2 percentage points and with 95% confidence the difference in the proportion of her male and female constituents who favor the bill. What sample size should she obtain?
Answers
Answer:
The sample size is [tex]n = 2401[/tex]
Step-by-step explanation:
From the question we are told that
The margin of error is [tex]E= 2\% = 0.02[/tex]
Given that the confidence level is 95% then the level of significance is mathematically evaluated as
[tex]\alpha = (100 - 95)\%[/tex]
[tex]\alpha = 5\% = 0.05[/tex]
The critical value of [tex]\frac{\alpha }{2}[/tex] obtained from the normal distribution table is [tex]Z_{\frac{\alpha }{2} } = 1.96[/tex]
Let assume that the sample proportion is [tex]\r p = 0.5[/tex]
Generally the sample size is evaluated as
[tex]n = [\frac{Z_{\frac{\alpha }{2} }}{E} ]^2 * \r p ( 1- \r p )[/tex]
[tex]n = [\frac{1.96}{0.02} ]^2 * 0.5 ( 1- 0.5 )[/tex]
[tex]n = 2401[/tex]
How do I solve these equations:
sin(2θ) + sin θ = 0
sin(2θ) = sqrt 3 cos θ
for intervals 0=< θ < 2pi
Answers
Answer:
Step-by-step explanation:
Given that
sin(2θ)+sinθ=0
We know that
sin(2θ)=2 sinθ x cosθ
Therefore
2 sinθ x cosθ + sinθ=0
sinθ(2 cosθ+1)=0
sinθ= 0
θ=0
2 cosθ+1=0
cosθ= - 1/2
θ=120°
_______________________________________________________
[tex]sin 2\theta=\sqrt{3cos\theta}[/tex]
By squaring both sides
[tex]sin^2 2\theta={3cos\theta}[/tex]
4 sin²θ x cos²θ=3 cosθ
4 sin²θ x cos²θ - 3 cosθ=0
cos θ = 0
θ= 90°
4 sin²θ=3
θ=60°
A major traffic problem in the Greater Cincinnati area involves traffic attempting to cross the Ohio River from Cincinnati to Kentucky using Interstate 75. Let us assume that the probability of no traffic delay in one period, given no traffic delay in the preceding period, is 0.9 and that the probability of finding a traffic delay in one period, given a delay in the preceding period, is 0.6. Traffic is classified as having either a delay or a no-delay state, and the period considered is 30 minutes.Required:a. Assume that you are a motorist entering the traffic system and receive a radio report of a traffic delay. What is the probability that for the next 60 minutes (two time periods) the system will be in the delay state?b. What is the probability that in the long run the traffic will not be in the delay state?c. An important assumption of the Markov process model presented here has been the constant or stationary transition probabilities as the system operates in the future. Do you believe this assumption should be questioned for this traffic problem? Explain.
Answers
Answer:
a) 0.36
b) 0.3
c) Yes
Step-by-step explanation:
Given:
Probability of no traffic delay in one period, given no traffic delay in the preceding period = P(No_Delay) = 0.9
Probability of finding a traffic delay in one period, given a delay in the preceding period = P(Delay) = 0.6
Period considered = 30 minutes
a)
Let A be the probability that for the next 60 minutes (two time periods) the system will be in the delay state:
As the Probability of finding a traffic delay in one period, given a delay in the preceding period is 0.6 and one period is considered as 30 minutes.
So probability that for the next two time periods i.e. 30*2 = 60 minutes, the system in Delay is
P(A) = P(Delay) * P(Delay) = 0.6 * 0.6 = 0.36
b)
Let B be the probability that in the long run the traffic will not be in the delay state.
This statement means that the traffic will not be in Delay state but be in No_Delay state in long run.
Let C be the probability of one period in Delay state given that preceding period in No-delay state :
P(C) = 1 - P(No_Delay)
= 1 - 0.9
P(C) = 0.1
Now using P(C) and P(Delay) we can compute P(B) as:
P(B) = 1 - (P(Delay) + P(C))
= 1 - ( 0.6 + 0.10 )
= 1 - 0.7
P(B) = 0.3
c)
Yes this assumption should be questioned for this traffic problem because it implies that traffic will be in Delay state for the 30 minutes and just after 30 minutes, it will be in No_Delay state. However, traffic does not work like this in general and it makes this scenario unrealistic. Markov process model can be improved if probabilities are modeled as a function of time instead of being presented as constant (for 30 mins).
Solve the following system of eq ions. Express your answer as an ordered
pair in the format (a,b), with no spaces between the numbers or symbols.
3x + 4y=17
- 4x – 3y= - 18
Answer here
Answers
Answer:
(3,2)
Step-by-step explanation:
3x + 4y=17
- 4x – 3y= - 18
Multiply the first equation by 4
4(3x + 4y=17 )
12x +16y = 68
Multiply the second equation by 3
3( - 4x – 3y= - 18)
-12x -9y = -54
Add the new equations together to eliminate x
12x +16y = 68
-12x -9y = -54
-----------------------
7y = 14
Divide by 7
7y/7 = 14/7
y=2
Now find x
3x+4(2) = 17
3x+8 = 17
Subtract 8 from each side
3x+8-8 = 17-8
3x = 9
Divide by 3
x = 3
The margin of error ________ (increases or decreases) with an increased sample size and ________ (increases or decreases) with an increase in confidence level.
Answers
With such a larger sample size, the margin of error lowers (grows or decreases), whereas, at a higher confidence level, it increases (increases or declines).
The margin of error:
A margin of error increases as the confidence level rises, resulting in a larger interval. A margin of error is reduced as confidence is increased, resulting in a narrower interval.By increasing sample size and confidence level, the margin of error lowers and grows.
Margin of error [tex](E) = Z_c * {\frac{\sigma}{\sqrt{n}}}[/tex]
Here [tex]Z_c[/tex] denotes the confidence level's critical value.Whenever it comes to sample size, n is the number of people who take part in the study.As a result, the margin of error lowers as the sample size grows, and the margin of error increases as the confidence level grows.Find out more about the margin of error here:
brainly.com/question/10501147
What information do you need in order to determine the total distance Sam drives versus the actual displacement between his starting and ending points?
Answers
Answer:
his path
Step-by-step explanation:
In order to determine the total distance driven from one place to another, you need to know the path taken.
What is the 25th term in the following arithmetic sequence? -7, -2, 3, 8, ...
Answers
Answer:
108.
Step-by-step explanation:
-7, -2, 3, 8 is an arithmetic sequence with a1 (first term) = -7 and common difference (d) = 5.
The 24th term = a1 + (24 - 1)d
= -7 + 23 * 5
= -7 + 115
= 108.
Please Show Work
Need Help
Answers
Answer:
The distance is 87.5 miles
Step-by-step explanation:
We can use a ratio to solve
1 in 3.5 inches
----------- = ----------------
25 miles x miles
Using cross products
1x = 3.5 * 25
x =87.5
The distance is 87.5 miles
━━━━━━━☆☆━━━━━━━
▹ Answer
87.5 miles
▹ Step-by-Step Explanation
[tex]\frac{1}{25} * \frac{3.5}{x} \\\\1 * 3.5 = 3.5\\25 * 3.5 = 87.5 \\\\Actual Distance = 87.5 miles[/tex]
Hope this helps!
CloutAnswers ❁
━━━━━━━☆☆━━━━━━━
Jerry walked a dog from 6:40 a.m. to 7:30 a.m. one day. If he was paid at the rate of $6 per hour, how much did he cam that day?
Answers
Explanation:
1hr = 6$ but 1hr = 60min
Or 60min = 6$
If he walk the dog for 50min:
60/50 = 6/x
X = (6 x 50)/60
X = 300/60
X = 5$
X is the amount he was paid for walking the dog for 50 min.
And 7:30 - 6:40 = 50min
Find the odds in favor and the odds against a randomly selected person from Country X, age 25 and over, with the stated amount of education. four years (or more) of college
Answers
Answer:
25 : 63 and 63 : 25
Step-by-step explanation:
This is a complete question
The table shows the educational attainment of the population of Country X, ages 25 and over. Use the data in the table, expressed in millions, to solve the problem. of 10 questions ge 1: Ages 25 and Over, in Miltions 4 Years igh College 4 Years High School (Less than College School Only 4years) Cor Moce) Total Male 29 19 25 89 Female 11 28 23 Total 2 57 42 50 [176 Find the odds in favor and the odds against a randomty selected person from Country X.age 25 and over, with the stated amount of education. four years (or more) of college 21:67, 67:21 63:88, 88:63 25:63, 63:25 25:88, 88:25
According to the question, the relevant data provided in the question for the solution is as follows
Four years or more of college
Number of students = 50
Total = 176 students
Number of students does not belong = 126
So odds in favor is
= 50 : 126
= 25 : 63
And automatically out against the favor is 63 : 25
Please answer this correctly without making mistakes
Answers
Answer:
1/8
Step-by-step explanation:
3/8-1/8-1/8=1/8
The distance that Sarah travels varies directly to how long she drives. She travels 440 miles in 8 hours. Write the equation that relates the distance, d, to the time, t. How many miles can Sarah travel in 6 hours?
Answers
Answer:
330
Step-by-step explanation:
If d = distance, t = time, and s = speed, then the relationship between the 3 is s * t = d.
Solve for speed by dividing the distance over the time, s = d/t. Then, plug in the speed which in this case is 55 mph and then multiply by the time of 6 hours.
In a Gallup poll of randomly selected adults, 66% said that they worry about identity theft. For a group of 1013 adults, the mean of those who do not worry about identify theft is closest to ________.
Answers
Answer: 669
Step-by-step explanation:
Given, In a Gallup poll of randomly selected adults, 66% said that they worry about identity theft.
i.e. The proportion of adults said that they worry about identity theft. (p) = 0.66
Sample size : n= 1013
Then , Mean for the sampling distribution of sample proportion = np
= (1013) × (0.66)
= 668.58 ≈ 669 [Round to the nearest whole number]
Hence, the mean of those who do not worry about identify theft is closest to 669 .
16.50 and pays 20.00 in cash the change due is
Answers
Answer:
Change due is 3.50
Step-by-step explanation:
20.00-16.50 is 3.50
Answer: $3.50
Step-by-step explanation:
You subtract 20 from 16.50.
Draw two normal curves that have the same mean but different standard deviations. Describe the similarities and differences. Compare the two curves. The two curves will have ▼ the same line different lines of symmetry. The curve with the larger standard deviation will be ▼ more less spread out than the curve with the smaller standard deviation.
Answers
Answer:
The same mean ⇒ the same symmetry axis
Bigger standard deviation major spread
Step-by-step explanation: See Annex
The annex shows two different normal curves:
1.- N (μ₀ ; σ₁ )
2.- N (μ₀ ; σ₂ )
Where σ₁ > σ₂
They both have the same symmetry axis ( they have the same mean and both curves have to be symmetrically related to the mean )
Normal distribution curves spread symmetrically at both sides of the mean, but the wider curve is the one that has the bigger standard deviation. Standard deviation is a measure of the spread of the curve.
Whenever deviation is high, the data is more dispersed than when deviation is low.
Let the mean be 2.
Let the standard deviation be 0.3 for first graph. The data is more clustered around mean.
Let the standard deviation be 0.6 for second graph. The data is less clustered more dispersed from mean.
For more information, refer this link:
https://brainly.com/question/12421652
Suppose log subscript a x equals 3, log subscript a y equals 7, and log subscript a z equals short dash 2. Find the value of the following expression. log subscript a open parentheses fraction numerator x cubed y over denominator z to the power of 4 end fraction close parentheses
Answers
Answer:
24Step-by-step explanation:
Given the following logarithmic expressions [tex]log_ax = 3, log_ay = 7, log_az = -2[/tex], we are to find the value of [tex]log_a(\frac{x^3y}{z^4} )[/tex]
[tex]from\ log_ax = 3, x = a^3\\\\from\ log_ay = 7,y = a^7\\\\from\ log_az = -2, z = a^{-2}[/tex]Substituting x = a³, y = a⁷ and z = a⁻² into the log function [tex]log_a(\frac{x^3y}{z^4} )[/tex] we will have;
[tex]= log_a(\frac{x^3y}{z^4} )\\\\= log_a(\dfrac{(a^3)^3*a^7}{(a^{-2})^4} )\\\\= log_a(\dfrac{a^9*a^7}{a^{-8}} )\\\\= log_a\dfrac{a^{16}}{a^{-8}} \\\\= log_aa^{16+8}\\\\= log_aa^{24}\\\\= 24log_aa\\\\= 24* 1\\\\= 24[/tex]
Hence, the value of the logarithm expression is 24
Suppose that 45% of people have dogs. If two people are randomly chosen, what is the probability that they both have a dog
Answers
Answer:
[tex]P(Dogs) = 0.2025[/tex]
Step-by-step explanation:
Given
[tex]Proportion, p = 45\%[/tex]
Required
Probability of two people having dog
First, we have to convert the given parameter to decimal
[tex]p = \frac{45}{100}[/tex]
[tex]p = 0.45[/tex]
Let P(Dogs) represent the required probability;
This is calculated as thus;
P(Dogs) = Probability of first person having a dog * Probability of second person having a dog
[tex]P(Dogs) = p * p[/tex]
[tex]P(Dogs) = 0.45 * 0.45[/tex]
[tex]P(Dogs) = 0.45^2[/tex]
[tex]P(Dogs) = 0.2025[/tex]
Hence, the probability of 2 people having a dog is [tex]P(Dogs) = 0.2025[/tex]
change 4 5/9 from a mixed number to an improper fraction
Answers
Step-by-step explanation:
Hello, there!!
The answer would be 41/9.
The reason for above answer is to change any mixed fraction into improper fraction we should follow a simple step:
multiply the denominator with whole number.Add the answer (after mutiplied ).look here,
=[tex] \frac{4 \times 9 + 5}{9} [/tex]
we get 41/9.
Hope it helps...
The given fraction into the improper fraction should be [tex]\frac{41}{9}[/tex]
Given that,
The mixed number fraction is [tex]4 \frac{5}{9}[/tex]Computation:[tex]= 4\frac{5}{9}\\\\ = \frac{41}{9}[/tex]
Here we multiply the 9 with the 4 it gives 36 and then add 5 so that 41 arrives.
learn more about the fraction here: https://brainly.com/question/1301963?referrer=searchResults
Please help me with this
Answers
Answer:
Median; 60
Step-by-step explanation:
For a data plot as shown in the question above, one easier measure of center that can be used for the data set represented is the median.
From the dot plot, we can easily pinpoint the exact median, which can be used as a measure of center.
There are 11 data points represented on the dot plot by 11 dots. The median, that is the median value of the data set, would be the 6th value represented by the 6th dot on the dot plot.
Thus, the middle value is 60.
60 is the median of the data set.
Students who score within 14 points of the number 88 will pass a particular test. Write this statement using absolute value notation and use the variable x for the score.
Answers
Answer:
|88-x| ≤ 14
Step-by-step explanation:
their score has to be within 14 points of 88.
if their score is above 88, the number will be negative, but the absolute value makes the number positive. if that number is still within 14 of 88, they pass.
if their score is below 88, the number will be negative, and the absolute value keeps the number positive. if that number is still within 14 of 88, they pass.
NEED HELP ASAP
Which point represents the center of the circle shown below?
Answers
Answer:
Point O represents the center of the circle
Step-by-step explanation:
HOPE IT HELPS. PLEASE MARK IT AS BRAINLIEST
Explanation:
Point O is in the middle of the circle
And other point are not in the middle
Which equations has no solution?
Answers
Answer: I think it is C
Step-by-step explanation:
There is no answer because A can be many solutions, B is x = -25, you just cannot solve C, and D is y = 7/6
An honest die is rolled. If the roll comes out even (2, 4, or 6), you will win $1; if the roll comes out odd (1,3, or 5), you will lose $1, Suppose that in one evening you play this game n=2500 times in a row.
(a) Estimate the probability that by the end of the evening you will not have lost any money.
(b) Estimate the probability that the number of "even rolls" (roll a 2, 4, or 6) will fall between 1250 and 1300.
(c) Estimate the probability that you will win $100 or more.
Answers
Answer:
(a) 50%
(b) 47.5%
(c) 2.5%
Step-by-step explanation:
According to the honest coin principle, if the random variable X denotes the number of heads in n tosses of an honest coin (n ≥ 30), then X has an approximately normal distribution with mean, [tex]\mu=\frac{n}{2}[/tex] and standard deviation, [tex]\sigma=\frac{\sqrt{n}}{2}[/tex].
Here the number of tosses is, n = 2500.
Since n is too large, i.e. n = 2500 > 30, the random variable X follows a normal distribution.
The mean and standard deviation are:
[tex]\mu=\frac{n}{2}=\frac{2500}{2}=1250\\\\\sigma=\frac{\sqrt{n}}{2}=\frac{\sqrt{2500}}{2}=25[/tex]
(a)
To not lose any money the even rolls has to be 1250 or more.
Since, μ = 1250 it implies that the 50th percentile is also 1250.
Thus, the probability that by the end of the evening you will not have lost any money is 50%.
(b)
If the number of "even rolls" is 1250, it implies that the percentile of 1250 is 50th.
Then for number of "even rolls" as 1300,
1300 = 1250 + 2 × 25
= μ + 2σ
Then P (μ + 2σ) for a normally distributed data is 0.975.
⇒ 1300 is at the 97.5th percentile.
Then the area between 1250 and 1300 is:
Area = 97.5% - 50%
= 47.5%
Thus, the probability that the number of "even rolls" will fall between 1250 and 1300 is 47.5%.
(c)
To win $100 or more the number of even rolls has to at least 1300.
From part (b) we now 1300 is the 97.5th percentile.
Then the probability that you will win $100 or more is:
P (Win $100 or more) = 100% - 97.5%
= 2.5%.
Thus, the probability that you will win $100 or more is 2.5%.
10. A sample of 60 mutual funds was taken and the mean return in the sample was 13% with a standard deviation of 6.9%. The return on a particular index of stocks (against which the mutual funds are compared) was 11.5%. Therefore, the test statistic is 1.68. When testing the hypothesis that the average return on actively-managed mutual funds is higher than the return on an index of stocks, if the critical value is 1.96, what is your conclusion concerning the null hypothesis
Answers
Answer:
In this question, we shall be accepting the null hypothesis H0 since the critical value is greater than the test statistic value
Step-by-step explanation:
Here in this question, we want to make a conclusion about the null hypothesis H0.
To make or give the correct conclusion about the null hypothesis in this case, we shall need to compare the absolute value of the test statistic used against the value of the critical value.
Hence, we draw a conclusion if the test statistic is larger or smaller than the critical value.
From the value given in the question, we can see that the test statistic given as 1.68 is lesser in value compared to the critical value given as 1.96.
In this kind of case, the conclusion that we shall be drawing is that we will accept the null hypothesis H0 and reject the alternative hypothesis
BRAINLIEST IF CORRECT!!! and 15 points solve for z -cz + 6z = tz + 83
Answers
Answer:
z = 83/( -c+6-t)
Step-by-step explanation:
-cz + 6z = tz + 83
Subtract tz from each side
-cz + 6z -tz= tz-tz + 83
-cz + 6z - tz = 83
Factor out z
z( -c+6-t) = 83
Divide each side by ( -c+6-t)
z( -c+6-t)/( -c+6-t) = 83/( -c+6-t)
z = 83/( -c+6-t)
Can I have help with 43 and 44 I need to see how to do them thanks.
Answers
Answer:
see explanation
Step-by-step explanation:
(43)
3[tex]x^{5}[/tex] - 75x³ ← factor out 3x³ from each term
= 3x³(x² - 25) ← this is a difference of squares and factors in general as
a² - b² = (a - b)(a + b) , thus
x² - 25 = x² - 5² = (x - 5)(x + 5)
Thus
3[tex]x^{5}[/tex] - 75x³ = 3x³(x - 5)(x + 5)
(44)
81c² + 72c + 16 ← is a perfect square of the form
(ac + b)² = a²c² + 2abc + b²
Compare coefficients of like terms
a² = 81 ⇒ a = [tex]\sqrt{81}[/tex] = 9
b² = 16 ⇒ b = [tex]\sqrt{16}[/tex] = 4
and 2ab = 2 × 9 × 4 = 72
Thus
81c² + 72c + 16 = (9c + 4)²
1. 3x^5 -75x³
=3x³(x²-25)
=3x³(x²-5²)
=3x³(x-5)(x+5)
2. 81c²+72c+16
=81c²+36c+36c+16
=9c(9c+4)+4(9c+4)
=(9c+4)(9c+4)
=(9c+4)²
20 points!
Please help.
