Answer:
18x +27
Step-by-step explanation:
-9(-2x-3)
Distribute
-9 * -2x -9*(-3)
18x +27
help please!!
For the following situation, identify the explanatory and response variable. Then discuss what reservations (think cautions) you might have about the results of the experiment. Asking “What if…” type questions may help.
Do the high, centered brake lights (which have been required on all U.S. cars since 1986) really reduce the frequency of rear-end collisions? Randomized comparative experiments with fleets of rental and business cars, done before the lights were required, showed that the third brake light reduced rear-end collisions by as much as 50%. After the lights were required the drop was only 5%.
The experiment is messed up. Business and rental drivers are usually much more careful in their driving patterns because the car isn't theirs. They are usually adults, experienced drivers who don't put themselves into risky driving situations. = Speeding, cutting off others etc.. It also didn't tell how much the cars were driven. There may have been a down turn in the economy and thus less business driving and same with the rentals. If they were used less after the installation then the study wasn't really valid. What was the price of gas before and after the instillation. Who did the study? Did the previous testers have any reason to skew the study? Did they own stock in the third light business? Was it the same people who did the study before who did the study afterwords? What was the average age of the drivers before and after? The study group may have aged and calmed down a bit more? What were the technology changes that occurred about the same time? Anti skid brakes, better material and tread designs for the tires, what about the design of the gages and their lighting. How about the window styles and size..larger windows mean better view and potentially less accidents. What were the safety aspects of the cars before compared to the cars after, were they the same makes and Models or did the rental and business learn that certain cars were safer than others and move to the safer Models? so many variables to consider but did the tester consider them all-probably not. Random studies study only a certain percentage of the total. Who's to say the second random study didn't get less experienced drivers to study? All good what ifs'.
An environmental engineer is tasked with determining whether a power plant cooling system is heating the water it uses more than allowed by environmental regulations. They measure water temperatures at the cooling system input and the cooling system output for several different days in several different seasons.A data file containing these measurements is HW_PTA 243.csv.Do a statistical analysis on this data to determine if the temperature change between the input and output of the cooling system is different than 6 degrees. What does your analysis indicate?
A) The cooling system changes the temperature of the water by an amount different than 6 degrees.
B) The cooling system changes the temperature of the water by 6 degrees.
Complete Question
The complete question is shown on the first , second and third uploaded image
Answer:
A
The correct option is A
B
The correct option is H
Step-by-step explanation:
The null hypothesis is [tex]H_o : \mu_1 - \mu_2 = 6[/tex]
The alternative hypothesis is [tex]H_a : \mu_1 - \mu_2 \ne 6[/tex]
The population mean difference is [tex]\mu_d = 6[/tex]
Generally the sample size is n = 15
Generally the sample mean for input temperature is mathematically represented as
[tex]\= x _1 = \frac{\sum x_i }{n}[/tex]
=> [tex]\= x _1 = \frac{57.6 + 68.9 + \cdots +60.4 }{15}[/tex]
=> [tex]\= x _1 = 62.57 [/tex]
Generally the sample mean for output temperature is mathematically represented as
[tex]\= x _2 = \frac{\sum x_i }{n}[/tex]
=> [tex]\= x _2 = \frac{65.1+ 74.4 + \cdots +67.3 }{15}[/tex]
=> [tex]\= x _2 = 55.97 [/tex]
Generally the sample mean difference is mathematically represented as
[tex]\= d = 62.57 - 55.97[/tex]
=>[tex]d = 6.6[/tex]
Generally the standard deviation is mathematically represented as
[tex]s_d = \sqrt{\frac{ \sum [d_1 - \= d]^2}{n-1} }[/tex]
=> [tex]s_d = \sqrt{\frac{ [ [57.6 -65.1]- 6.6]^2 +[68.9 -74.4]- 6.6]^2+\cdots + [60.4 -67.3]- 6.6]^2}{15-1} }[/tex]
=> [tex]s_d = 1.732 [/tex]
Generally the test statistics is mathematically represented as
[tex]t = \frac{6.6 - 6 }{\frac{1.732}{\sqrt{15} } }[/tex]
=> [tex]t = 1.342 [/tex]
Generally the degree of freedom is mathematically represented as
[tex]df = n - 1[/tex]
So
[tex]df = 15 - 2[/tex]
=> [tex]df = 14[/tex]
Generally the p-value is mathematically represented as
[tex]p-value = 2 * P(t > 1.342 )[/tex]
Generally from the t -distribution table the probability of 1.342 at a degree of freedom of [tex]df = 28[/tex] is
[tex]P(t > 1.342 ) = 0.10047[/tex]
So
[tex]p-value = 2 * 0.10047[/tex]
=> [tex]p-value = 0.201[/tex]
Generally from the value obtained we see that [tex]p-value > \alpha[/tex] Hence
The decision rule is
Fail to reject the null hypothesis
The conclusion is
The cooling system changes the temperature of the water by 6 degrees
1 3 Divide - 2 +7=Explain each step you used to find the quotient. 9 5 What is the first step in finding this quotient? Select the correct choice below and fill in the answer box to complete your choice. (Type an integer or a fraction. Use a comma to separate answers as needed.) O A. Multiply the whole parts of the mixed numbers. The product is OB. Multiply the fraction parts of the mixed numbers. The product is OC. Convert the mixed numbers to fractions. The fractions are OD. Find the reciprocal of the dividend. The reciprocal is
Answer: 15 an ummm fine
Step-by-step explanation:
Answer:
15 is the correct answer
five times the sum of a number and four
here is the Answer:
5(x+4)
Hope it helps
A vaccine is 95 percent effective. What is the probability that it is not effective for more than 1 out of 20 individuals?
Answer:
The probability that the vaccine is not effective in more than 1 of the 20 individuals is equal to:
P = 1 - P(1) - P(0)
Where:
P(1) = probability that the vaccine is not effective in one individual
P(0) = probability that the vaccine is not effective in 0 individuals.
The probability that the vaccine is effective is 0.95
Then the probability that the vaccine is not effective is 0.05.
Then to calculate P(1), suppose that the vaccine is not effective in the first case and then is effective 19 times, this is:
p(1) = (0.05^1)*(0.95^19)
But this only for one case, we have 20 possible permutations (the vaccine is not effective in the first case, the second case, third case, etc)
Then the actual probability is:
P(1) = 20*((0.05^1)*(0.95^19)) = 0.377
And P(0) is easy to compute:
P(0) = (0.05^0)*(0.95^20) = 0.358
And here we have only one possible permutation, so we do not worry about that.
Then P = 1 - P(1) - P(0) = 1 - 0.377 - 0.358 = 0.265
This means that the probability that the vaccine is not effective in more than one individual is of 0.265 (or 26.5% in percentage form)
no matter what answer i put in it always tells me I'm wrong so can someone actually help
Answer:
[tex]\frac{1}{9}[/tex]
Step-by-step explanation:
[tex]\frac{1}{3^2}=\frac{1}{3} *\frac{1}{3} =\frac{1}{9}[/tex]
1. Emma’s average in math increased from an 80 to an 84. By what percentage did her average increase?
Answer:
82
Step-by-step explanation:
Nicole used 3/8 of her ribbon to wrap a present. If she used 6 feet of ribbon for the present, how much ribbon did Nicole have at first?
Answer:
She had 16 feet of ribbon
Step-by-step explanation:
Answer:
16 ft of ribon
Step-by-step explanation:
divide 6 by 3 and get 2. there is 2 ft for every 8th of the ribbon so 2×8=16
hope it helped
How many kilograms of potatoes will each person get if 5 people share 1/3 of a kilogram of potatoes equally?
Answer:
1/15 kg
Step-by-step explanation:
Divide by 5 can be written as multiply by 1/5
1/3 * 1/5 = 1/15
2. I mark as brainliest
Answer:
3.55 miles
Step-by-step explanation:
You add the mileage of the two trails which is 1.75+1.8=3.55 miles
The neighborhood swimming pool drains at a rate of 99 gallons every 3 hours. At this rate, how many gallons are
emptied each hour?
Helllllpppppp meeee
Answer:
33mph
Step-by-step explanation:
because if u divide 99 by 3 that is the answer
15. To receive a B in his English class, Nicolas must have an average score of at least 84 on five
tests. He scored 90,91, 79, and 81 on his first four tests. What is the score range he can receive
on his last test and still receive a B in the class?
Answer:
(90+91+79+81+x)/5=84and 341+x=84*5and341+x=420and x=420-341 finally x=79
Define the following terms:
does anyone need to talk/rant about something because im here for you
Answer: sure
Step-by-step explanation:
Answer:
yes
Step-by-step explanation:
ok so I just got an email from my school saying that you need to do half the semester in ONE WEEK and I'm like, why you didn't need to do this. And also my parents are expecting me to do it ALL IN 2 DAYS AND GET AN A honestly I am very sad I am actually doing an assignment right now lol.
4.321 × 12.34 AND IF YOU ANSWER YOU GET 10 POINTS JUST PLS HELP
Answer:
53.32114
Step-by-step explanation:
Jin adds 1 gallon of a water-and-bleach mixture that is 4% bleach to 2 gallons of a
water-and-bleach mixture that is 10% bleach. What percent of the final mixture is bleach?
Answer:
0.08%
(might be wrong)
Step by step explanation:
0.04•1+0.10•2=3•x
0.04+0.2=3x
0.24=3x
x=0.08
Not sure if this is right
Answer: 8
Step-by-step explanation:
last year, emilia went bowling several times and earned an average score of 100 points. this year, after taking a class at school, her average is now 98% higher. what is her current average?
help ASAP. Which relation is a function?
Answer:
Answer choice on the top right.
Step-by-step explanation:
A function of points can not share the same x value.
Find the missing angle measures. (2x-3),(8x) and(x+7)
Answer:
2x-3 = 29
8x = 128
x+7 = 23
Step-by-step explanation:
The sum of the angles of a triangle is 180
2x-3 + 8x+ x+7 = 180
Combine like terms
11x+4 = 180
Subtract 4 from each side
11x+4-4= 180-4
11x = 176
Divide by 11
11x/11 =176/11
x =16
2x-3 = 2*16-3 =32-3 = 29
8x = 8*16 =128
x+7 = 16+7 = 23
I need help with this question
Answer:
1/3
Step-by-step explanation:
i hope this helps you! :)
Answer:
1/3
Step-by-step explanation:
When you are subtracting frations with the same denominator, you would only subtract the numerator and keep the denominator the same.
Find the number that makes the ratio equivalent to 7:8.
:24
Answer:
21:24
Step-by-step explanation:
7:8 is your ratio
so if _:24 is equivalent, you have to figure out what 24 is divisible by to equal 8
8×3=24
so now we have to multiply 7 by 3
7×3=21
so your answer is 21:24 = 7:8
hope this helps :)
What is the value of sin-1(cos(2pi/3))?
Answer:
-pi/6
Step-by-step explanation:
Answer:
-pi/6 c
Step-by-step explanation:
Rate of change is a ______ that describes how much one quantity ______ in respect to another
Answer:
A rate of change is a RATE that describes how one quantity CHANGES in relation to another quantity.capital and underlined is your answer
PLZ HURRY IT'S URGENT!!!
What is the slope of the line?
y=3
options:
0
1
3
undefined
Answer:
0
There is no x or number with an x (example: y= 2x+3, the 2 would be the slope)
Answer:
0
Step-by-step explanation:
what is 37737332732.83838-388733883.6 equal?
Answer:
4838388.34?
Step-by-step explanation:
¾ divid ⅖=n
Pleas answer i need a answer
please help me lol aaaaa
Answer:
−0.125 or - 1/8
Step-by-step explanation:
Chloe runs the after-school cookery club.
The group will be baking 36 scones using the following recipe.
Recipe for 12 scones:
• 250 g self-raising flour
• 60 g butter
• 30 g caster sugar
• 175 ml milk
How much milk will be used?
ml
Answer:
525 ml
Step-by-step explanation:
12 : 175 ml
36 : x
= 175 × 36
= 6300
x = 6300/12
= 525 ml
The amount of milk that is used while baking 36 scones will be 525 mL.
What are ratio and proportion?A ratio is a group of sequentially ordered numbers a and b expressed as a/b, where b is never equal to zero. When two objects are equal, a statement is said to be proportional.
Chloe runs the after-school cookery club. The group will be baking 36 scones using the following recipe.
Recipe for 12 scones:
250 g self-raising flour60 g butter30 g caster sugar175 mL milkThe amount of milk that is used while baking 36 scones will be given as,
⇒ 175 x 36 / 12
Simplify the expression, then we have
⇒ 175 x 36 / 12
⇒ 175 x 3
⇒ 525 mL
The amount of milk that is used while baking 36 scones will be 525 mL.
More about the ratio and the proportion link is given below.
https://brainly.com/question/14335762
#SPJ5
A man bought two books for RS 1040. He sold one at a loss of 15% and other at a profit of 36% then he found that each book was sold for the same price. Find the cost price of each book.
Answer:
640 & 400
Step-by-step explanation:
Cost of books: x and 1040-x
x sold at a loss of 15%= .85 x
1040 - x sold at a profit of 36% = (1040 - x) *1.36
x*.85= (1040-x)*1.36
0.85x+1.36x= 1040*1.36
2.21x= 1414.4
x= 1414.4/ 2.21
x= Rs. 640
Rs. 1040 - 640 = 400
Line t has a slope of 3/5 line u is perpendicular to t what is the slope of line u
Answer:
[tex]\frac{5}{3}[/tex] is the slope of the line
Step-by-step explanation:
When two lines are perpendicular, their slopes are inverse.
[tex]\frac{3}{5}[/tex] becomes [tex]\frac{5}{3}[/tex] because they are inverse. Just flip the numerator (top number) and denominator(bottom number).
Hope this helps!