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
Nina [5.8K]
3 years ago
11

Suppose you work in the quality assurance department of a chemical processing plant and it is your responsibility to ascertain w

hether the viscosity of a certain chemical remains within a prescribed limit. To that end you measure fluid samples using a viscometer. a. The viscosities of a sample of 10 fluids processed during the day shift were measured to have the following results (Pa.s): 71, 45, 54, 75, 50, 49, 63, 55, 48, 50. Determine the range within which the true mean of the fluid samples from the day shift will be with a 95% confidence.
Mathematics
1 answer:
aleksandrvk [35]3 years ago
6 0

Answer:

48.668 ≤ μ ≤ 63.332

Step-by-step explanation:

Given the data:

Sample (X) : 71, 45, 54, 75, 50, 49, 63, 55, 48, 50

Number of samples (n) = 10

α = 95% = 0.05

Determine the range within which the true mean of the fluid samples from the day shift will be with a 95% confidence

True mean = μ

Confidence interval :

m ± t(α/2 ; df) * s/√n

m - t(α/2 ; df) * s/√n ≤ μ ≤ m + t(α/2 ; df) * s/√n

m = sample mean ; s = sample standard deviation ; df = degree of freedom =(n - 1) = (10 - 1) = 9

Calculating the sample mean and standard deviation using calculator to save computation time :

71, 45, 54, 75, 50, 49, 63, 55, 48, 50

m = 56 ; s = 10.25

m - t(0.05/2 ; 9) * s/√n ≤ μ ≤ m + t(0.05/2 ; df) * s/√n

From t table : t(0.05/2 ; 9) = t(0.025, 9) = 2.262

56-2.262 * (10.25/√10) ≤ μ ≤ 56+2.262 * (10.25/√10)

48.668 ≤ μ ≤ 63.332

You might be interested in
Two trains arrived at a station at 2:55 P.M., with one arriving on Track A, and the other arriving on Track B. Trains arrive on
My name is Ann [436]

Answer:

B) 5:19 P.M.

Step-by-step explanation:

Given that two trains arrived at a station at 2:55 P.M., with one arriving on Track A, and the other arriving on Track B. Trains arrive on Track A every 16 minutes, and they arrive on Track B every 18 minutes.

Now we need to find about at what time will trains next arrive at the same time on both tracks.

Then next time trains arrive at the same time on both tracks. can be found by taking least common multiple of 16 and 18 minutes.

Multiples of 16 and 18 are

16 32 48 64 80 96 112 128 144 160

18 36 54 72 90 108 126 144 162 180

Least common multiple of both is 144

Hence both trains will arrive at the same time after 144 minutes

or at (2:55 PM+144 minutes)

= (2 hours 55 min)+(144 min) PM

= (2 hours 55 min)+(2 hours 24 min) PM

= (2 hours 55 min)+(2 hours 24 min) PM

= 5 hours 19 minutes

Hence correct choice is B) 5:19 P.M.

7 0
3 years ago
Work out 2.9 cos 17° rounded to 2 d.p.
kirill115 [55]

Answer:

2.77

Step-by-step explanation:

2.9 cos (17) = 2.77

6 0
2 years ago
Read 2 more answers
In a MBS first year class, there are three sections each including 20 students. In the first section, there are 10 boys and 10 g
KIM [24]

Answer:

3.52 \times 10^{-9} = 3.52 \times 10^{-7}\% probability that all the 15 students selected are girls

Step-by-step explanation:

The selection is from a sample without replacement, so we use the hypergeometric distribution to solve this question.

Hypergeometric distribution:

The probability of x sucesses is given by the following formula:

P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}

In which:

x is the number of sucesses.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

C_{n,x} is the number of different combinations of x objects from a set of n elements, given by the following formula.

C_{n,x} = \frac{n!}{x!(n-x)!}

All girls from the first group:

20 students, so N = 20

10 girls, so k = 10

5 students will be selected, so n = 5

We want all of them to be girls, so we find P(X = 5).

P_1 = P(X = 5) = h(5,20,5,10) = \frac{C_{10,5}*C_{10,5}}{C_{20,5}} = 0.0163

All girls from the second group:

20 students, so N = 20

5 girls, so k = 5

5 students will be selected, so n = 5

We want all of them to be girls, so we find P(X = 5).

P_2 = P(X = 5) = h(5,20,5,5) = \frac{C_{5,5}*C_{15,5}}{C_{20,5}} = 0.00006

All girls from the third group:

20 students, so N = 20

8 girls, so k = 8

5 students will be selected, so n = 5

We want all of them to be girls, so we find P(X = 5).

P_3 = P(X = 5) = h(5,20,5,8) = \frac{C_{8,5}*C_{12,5}}{C_{20,5}} = 0.0036

All 15 students are girls:

Groups are independent, so we multiply the probabilities:

P = P_1*P_2*P_3 = 0.0163*0.00006*0.0036 = 3.52 \times 10^{-9}

3.52 \times 10^{-9} = 3.52 \times 10^{-7}\% probability that all the 15 students selected are girls

7 0
3 years ago
In expansion of (2x+1)(x^2+px+4), the coefficient of x is twice the coefficient of x^2.
Brilliant_brown [7]

You're probably supposed to find the value of p and not x, which is impossible to do.

Expanding gives

(2x+1)(x^2+px+4)=2x^3+(1+2p)x^2+(8+p)x+4

We're told that

8+p=2(1+2p)

which we can use to solve for p:

8+p=2+4p

6=3p

\boxed{p=2}

7 0
3 years ago
Which of the following describes muckrakers.
Evgesh-ka [11]

Answer:

I think it's A

Step-by-step explanation:

6 0
3 years ago
Other questions:
  • Algebra 2 unit 5 please help
    6·1 answer
  • What is the plural name for mitochondrion?
    10·2 answers
  •                                              .....................................
    11·1 answer
  • Please help me, which of the following sets of ordered pairs is a function?
    7·1 answer
  • I need help asap quick
    12·1 answer
  • Nicole plans to watch 3 movies each month . Write an equation to represent the total number of movies n that she will watch in m
    8·1 answer
  • Help pls! Giving brainliest!!!!!
    14·1 answer
  • Tell whether the two rates form a proportion
    10·2 answers
  • If a line has an undefined slope, what type of line is it classified as? (Check your spelling!)
    8·1 answer
  • Fourty mins after 4:40 is fourty mins before…
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!