1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Aleks04 [339]
2 years ago
8

Two different formulations of an oxygenated motor fuel are being tested to study their road octanenumbers. The variance of road

octane number for formulation 1 is ı2 = 1.5, and for formulation, 2it is ı2 = 1.2. Two random samples of size n1 = 15 and n2 = 20 are tested, and the mean roadoctane numbers observed are x1 = 89.6 and x2 = 92 5. Assume normality. Find the 95%confidence interval for the difference in the mean octane number.
Mathematics
1 answer:
Lyrx [107]2 years ago
3 0

Answer:chomai

Step-by-step explanation:chomai

You might be interested in
Three times the sum of a number and seven is two less than five times the number. . a. 3x+7=5x-2. b. 3(x+7)=5x-2. c. 3(x+7)=2-5x
Nuetrik [128]
<span>We dissect each statement from the problem above to fully understand it.

the sum of a number and 7 is (x + 7)

3 times this is 3(x + 7)

is means the equal sign here </span><span>3(x + 7) = </span><span>

Two less then 5 times the number is 5x - 2.

Therefore, the answer is B, 3(x + 7) = 5x - 2</span>
5 0
2 years ago
Ms. Dunn spent 10.70 buying slices of pie and cookies. She bought a total of 24 items. A slice of pie costs 0.80 and a cookie co
Rus_ich [418]

Answer:

Ms. Dunn bought 7 slices of pie.

Step-by-step explanation:

With the information provided, you can write the following equations:

x+y=24 (1)

0.80x+0.30y=10.70 (2), where:

x is the number of slices of pie

y is the number of cookies

First, you can solve for x in (1):

x=24-y (3)

Next, you have to replace (3) in (2) and solve for y:

0.80(24-y)+0.30y=10.70

19.2-0.80y+0.30y=10.70

19.2-10.70=080y-0.30y

8.5=0.5y

y=8.5/0.5

y=17

Finally, you can replace the value of y in (3) to be able to find the value of x:

x=24-17

x=7

According to this, the answer is that Ms. Dunn bought 7 slices of pie.

7 0
3 years ago
A new car dealer offered to sell her demonstrator model for 90% of the retail price. If the sale price was $9,750, what was the
Rainbow [258]
The answer would be 10833.3 
4 0
3 years ago
Read 2 more answers
Separated by or signs ​
Mademuasel [1]

Answer:

4242

Step-by-step explanation:

car is the best

3 0
3 years ago
Read 2 more answers
4.One attorney claims that more than 25% of all the lawyers in Boston advertise for their business. A sample of 200 lawyers in B
AleksAgata [21]

Answer:

z=\frac{0.315 -0.25}{\sqrt{\frac{0.25(1-0.25)}{200}}}=2.123  

p_v =P(Z>2.123)=0.0169  

The p value obtained was a very low value and using the significance level given \alpha=0.05 we have p_v so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of lawyers had used some form of advertising for their business is significantly higher than 0.25 or 25% .  

Step-by-step explanation:

1) Data given and notation  

n=200 represent the random sample taken

X=63 represent the lawyers had used some form of advertising for their business

\hat p=\frac{63}{200}=0.315 estimated proportion of lawyers had used some form of advertising for their business

p_o=0.25 is the value that we want to test

\alpha=0.05 represent the significance level

Confidence=95% or 0.95

z would represent the statistic (variable of interest)

p_v represent the p value (variable of interest)  

2) Concepts and formulas to use  

We need to conduct a hypothesis in order to test the claim that more than 25% of all the lawyers in Boston advertise for their business:  

Null hypothesis:p\leq 0.25  

Alternative hypothesis:p > 0.25  

When we conduct a proportion test we need to use the z statistic, and the is given by:  

z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}} (1)  

The One-Sample Proportion Test is used to assess whether a population proportion \hat p is significantly different from a hypothesized value p_o.

3) Calculate the statistic  

Since we have all the info requires we can replace in formula (1) like this:  

z=\frac{0.315 -0.25}{\sqrt{\frac{0.25(1-0.25)}{200}}}=2.123  

4) Statistical decision  

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.  

The significance level provided \alpha=0.05. The next step would be calculate the p value for this test.  

Since is a right tailed test the p value would be:  

p_v =P(Z>2.123)=0.0169  

The p value obtained was a very low value and using the significance level given \alpha=0.05 we have p_v so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of lawyers had used some form of advertising for their business is significantly higher than 0.25 or 25% .  

8 0
3 years ago
Other questions:
  • A) 90
    13·1 answer
  • A flagpole that is 30 feet tall casts a shadow that extends 42 feet from the base of the flagpole. What is the distance from the
    14·1 answer
  • Investing is a game of chance. Suppose there is a 36% chance that a risky stock investment will end up in a total loss of your i
    14·1 answer
  • Solve for d 41=12d-7 thank you
    6·2 answers
  • The rough estimate of the perimeter of a rectangle of length 3.67 cm and width 2.54cm
    9·1 answer
  • Brine is a solution of salt and water. If a tub contains 50 gallons of a 5% solution of brine, how much water must evaporate to
    7·1 answer
  • Please help question in the picture
    11·1 answer
  • What is the mean of the set of data? 18, 11, 16, 8, 16, 21 plz help
    6·1 answer
  • ASAP Ben fold 126 and 200 and his first two games what must he Bowl in his third game to get an average of at least 190​
    11·2 answers
  • Please help me I don't understand this
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!