A simple random sample of 8 reaction times of NASCAR drivers is selected. The reaction times have a normal distribution. The sample mean is 1.24

sec with a standard deviation of 0.12 sec. Construct a 99% confidence interval for the population standard deviation

Answers

Answer 1

Answer:

99% confidence interval is 0.07 < σ < 0.32

Step-by-step explanation:

Given that;

standard deviation s = 0.12 sec

s² = 0.12² = 0.0144

degree of freedom DF = n - 1 = 8 - 1 = 7

99% confidence interval

∝ = 1 - 99% = 1 - 0.99 = 0.01

now, we find x² critical values for ∝/2 = 0.005 and 1 - ∝/2 = ( 1 - 0.005) = 0.995, df = 7

The Lower critical value [tex]X^{2}_{\frac{\alpha }{2}},7[/tex] = 20.2777

The Upper critical value [tex]X^{2}_{1-{\frac{\alpha }{2}},7[/tex] = 0.9893

Now, confidence interval is given by

√[ ( (n-1)×s² ) / ( [tex]X^{2}_{\frac{\alpha }{2}},7[/tex] ) ] < σ < √[ ( (n-1)×s² ) / (  [tex]X^{2}_{1-{\frac{\alpha }{2}},7[/tex]  ) ]

so we substitute

√[ ( 7×0.0144 ) / ( 20.2777 ) ] < σ < √[ ( 7×0.0144 ) / ( 0.9893 ) ]

√[ ( 7×0.0144 ) / ( 20.2777 ) ] < σ < √[ ( 7×0.0144 ) / ( 0.9893 ) ]

√0.0049711 < σ < √0.10189

0.0705 < σ < 0.3192

Rounding to the nearest 2 decimal places

0.07 < σ < 0.32

Therefore; 99% confidence interval is 0.07 < σ < 0.32


Related Questions

Quick I need some help! Simplify to create an equivalent expression. ( photo linked)

Answers

Answer:

B. 31r − 71 is the answer!

A construction worker drops a hammer while building the Grand Canyon skywalk 4,000ft above the Colorado River. Use the formula t=h‾√4 to find how many seconds it takes for the hammer to reach the river. Round your answer to the nearest tenth of a second.

Answers

Answer:

The hammer reaches the river after 15.8 seconds.

Step-by-step explanation:

The formula to find for how long it takes for the hammer to reach the ground is given by:

[tex]t = \frac{\sqrt{h}}{4}[/tex]

In which h is the initial height.

A construction worker drops a hammer while building the Grand Canyon skywalk 4,000ft above the Colorado River.

This means that [tex]h = 4000[/tex].

So

[tex]t = \frac{\sqrt{4000}}{4}[/tex]

[tex]t^2 = \frac{4000}{16}[/tex]

[tex]t^2 = 250[/tex]

[tex]t = \sqrt{250}[/tex]

[tex]t = 15.8[/tex]

The hammer reaches the river after 15.8 seconds.

Find a solution to the linear equation 13x+y=26

Answers

Answer:

y = -13x+26

Step-by-step explanation:

13x+y=26

y= -13x+26

Atatürk ordular ilk hedefimiz Akdeniz ileri emrini aşağıdaki savaşlardan hangisinde vermiştir a Sakarya savaşı b 1. İnönü c 2. İnönü d büyük taarruz​

Answers

Answer:

D şıkkı Büyük tarruz olmalı

“The length of the unknown side has to be greater than ___ and less than ___.” PLEASE HELP, WILL GIVE BRAINLIEST

Answers

Answer:

7< 8

Step-by-step explanation:

What is the degree of ADB

1.112°
2.86°
3.65°
4.68°

Answers

Answer:

I think it’s 1

Step-by-step explanation:

Because it’s a right triangle and it’s equal to 90° So

and 2,3,4 is less than 90 so

Which of the fractions is equivalent to 3/8?

A. 2/7

B. 8/3

C. 9/24

D. 5/10

Answers

Answer:

I think its C. 9/24

Step-by-step explanation:

Lillian wants to give 1/3 of a pizza to each of six girls at her party

Answers

Answer:

[tex]Fraction = \frac{1}{18}[/tex]

Step-by-step explanation:

Given

[tex]Pizza = \frac{1}{3}[/tex]

[tex]Girls = 6[/tex]

Required [Missing Information]

Determine the fraction each girl gets

To do this, we simply divide the pizza by the number of girls i.e.

[tex]Fraction = \frac{Pizza}{Girls}[/tex]

[tex]Fraction = \frac{1}{3} / 6[/tex]

Change / to *

[tex]Fraction = \frac{1}{3} *\frac{1}{6}[/tex]

[tex]Fraction = \frac{1}{18}[/tex]

Hence, each girl gets 1/18

IWHDHDNDJBFJDNX HELP!!!!!​

Answers

Answer:

The answer should be B.

Step-by-step explanation:

I got the answer before. Can't remember if I was right. Also A can also be correct.

Centerpieces are normally distributed with mean of 30 ounces and standard deviation of 2 ounces. The weights of the shipping boxes are normally distributed with mean of 12 ounces and standard deviation of 1 ounce. Suppose that centerpieces are chosen at random and packed into randomly chosen shipping boxes.If a package exceeds 45 ounces, an additional charge is incurred. What is the proportion of packages will incur such a charge

Answers

Answer:

0.0901 = 9.01% of packages will incur such a charge

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Sum of normal variables:

When we add normal variables, the mean will be the sum of the means, while the standard deviation is the square root of the sum of the variances.

Centerpieces are normally distributed with mean of 30 ounces and standard deviation of 2 ounces.

This means that [tex]\mu_C = 30, \sigma_C = 2[/tex]

The weights of the shipping boxes are normally distributed with mean of 12 ounces and standard deviation of 1 ounce.

This means that [tex]\mu_S = 12, \sigma_S = 1[/tex]

Suppose that centerpieces are chosen at random and packed into randomly chosen shipping boxes.

The shipment is given by the centerpice plus the shipping box. So the mean and the standard deviation of the weight are given by:

[tex]\mu = \mu_C + \mu_S = 30 + 12 = 42[/tex]

[tex]\sigma = \sqrt{\sigma_C^2 + \sigma_S^2} = \sqrt{2^2 + 1^2} = \sqrt{5} = 2.236[/tex]

If a package exceeds 45 ounces, an additional charge is incurred. What is the proportion of packages will incur such a charge

This proportion is 1 subtracted by the pvalue of Z when X = 45. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{45 - 42}{2.236}[/tex]

[tex]Z = 1.34[/tex]

[tex]Z = 1.34[/tex] has a pvalue of 0.9099

1 - 0.9099 = 0.0901

0.0901 = 9.01% of packages will incur such a charge

The students measured length during a science experiment,they got 12 cm.But the actual measurement was 14.25cm.what was the percent error?

Answers

Answer:

Percent error = 15.79%

Step-by-step explanation:

Given the following data;

Experimental value = 12cm

Actual value = 14.25cm

To find the percentage error;

Percent error can be defined as a measure of the extent to which an experimental value differs from the theoretical value.

Mathematically, it is given by this expression;

[tex] Percent \; error = \frac {experimental \;value - actual \; value}{ actual \;value} *100[/tex]

Substituting into the equation, we have;

[tex] Percent \; error = \frac {12 - 14.25}{14.25} *100[/tex]

[tex] Percent \; error = \frac {2.25}{14.25} *100[/tex]

[tex] Percent \; error = 0.1579 *100[/tex]

Percent error = 15.79%

Robert gets a job with a starting salary of $35,000. He is promised a $2500 raise each
subsequent year. Which of the following numbers represents his salary during his 7th
year of employment?
A. $45,000
B. $47,500
C. $50,000
D. $52,500

Answers

D.) $52,000----------------------------------

Step-by-step explanation:

starting salary = $35,000

raise in 1 year = $2500

raise in 7 year = $17,500

salary on 7th year = $35,000 + $17,500

= $52,500

-----------------------------------FOLLOW ME

A coin will be tossed three times, and each toss will be recorded as heads (H) or tails (7). Give the sample space describing all possible outcomes. Then give all of the outcomes for the event that the second toss is heads. Use the format HTH to mean that the first toss is heads, the second is tails, and the third is heads. If there is more than one element in the set, separate them with commas. Sample space: Event that the second toss is heads: 0 Х ?

Answers

Answer:

A). {HHH, HHT, HTH, THH, TTH,THT,HTT,TTT}

(B). {HHH, HHT, THH, THT}

Step-by-step explanation:

Given:

A coin is to be tossed three times and each tossed will be recorded as Head(H) and Tails(T).

To Find:

(a). Sample Space

(b). Event that the second toss is Heads

Explanation:

(A). Sample Space: When a coin is tossed 3 times

{HHH, HHT, HTH, THH, TTH,THT,HTT,TTT}

(B). Event that second toss is Head

{HHH, HHT, THH, THT}

There is a bag filled with 6 blue and 5 red marbles.
A marble is taken at random from the bag, the colour is noted and then it is replaced.
Another marble is taken at random.
What is the probability of getting exactly 1 blue?

Answers

Answer:

Step-by-step explanation:

Um

What is true about (0, 5)

Answers

Answer:

0/5 equals zero as anything divided by zero gives zero. However 5/0 is an undetermined form which gives infinity.

Step-by-step explanation:

Solve
2
X = 6.
x =
Help would be greatly appreciated

Answers

Answer:

x=3

Step-by-step explanation:

Lisa is making ethernet cables for Mrs. Houston in the computer lab. The spool of wire that she is creating the cables from is 40ft long. She creates 5 equal cables and has 12ft remaining. What was the length of each cable? (HOW DID YOU GET YOUR ANSWER PLEASE SHOW ME YOUR WORK!!)
A. 16.6%
B. 50%
C. 20%
D. 5.6FT
E. $29.40
F. $30.40
G. 6.3FT
H. 25%

Answers

Answer:

D. 5.6 ft

Step-by-step explanation:

40 ft - 12 ft = 28 ft    (You subtract the leftover wire(12 ft) from the total amount(40 ft) so you can see how much wire was used to make the 5 cables. There was 28 ft of wire in total used to create the 5 cables.) 28 ÷ 5 = 5.6 ft           (You divide 28 by 5 so that you can see how much wire was used for each cable.)Final Answer: The length of each cable was 5.6 ft or just 5.6 ft.

How could
you re-write the number 330 using the 4, 82 and the
remainder of 2 ?

Answers

Step-by-step explanation:

the answer for ur question is:

82(4)+2

Which values are solutions to the inequality square root of x is less than 8? A. 55 B. 8 C. -8 D. 4 E. 65 F. -64

Answers

9514 1404 393

Answer:

  A.  55

  B. 8

Step-by-step explanation:

We want ...

  √x < 8

  x < 8² . . . . . square both sides

  x < 64

In order for the inequality to make any sense, we must also have ...

  0 ≤ x

So, the solution space is ...

  0 ≤ x < 64

Only answer choices A (55) and B (8) are in that range.


Please I really need help I know it is not A

Answers

The answer is D :DDDDDDDDDDD

The line plot shows the amount of water collected after seven days of an experiment. Tina decides to evenly divide the water into 3 glas
Amount of Water
X
X
X X
+ +
1 1 3
0
2 4
Measurement (in cups)
1
How much water should go into each glass?
cup
O
1 cup
2 cups
3 cups

Answers

Answer: my brother did it and it's 1 cup

Step-by-step explanation:

Answer:

1 cup

Step-by-step explanation:

ive done this test in class if you need further explionation let me know

PLZ HELP! Sorry about the terrible picture but I had to take it quick cuz I need an answer fast.​

Answers

Answer:

it will 90° because it is making right angle at C

Answer:

40 digree is the answer

brooo I think it will help u

एक कार की गति 92.4 किमी प्रति घंटा है यह 20 मिनट मे कितना दुरी तय करेगी ​

Answers

Answer:

mate I will surely help if nut pls translate it in English as I can barely read hindi

Thirty-seven is less than the difference of seven and ten times a number.​

Answers

Answer:

37< 10x-7

Step-by-step explanation:

I think that’s why I looked it up god bless

If someone can help me with this question i’ll thank them forever!!

Answers

Answer:

[tex]-\frac{3}{2}[/tex] < x or x > 4

Step-by-step explanation:

Convert the inequality to an equation.

2x² - 5x = 12

2x² - 5x - 12 = 0

Factor by grouping.

(2x + 3)(x - 4) = 0

If any individual factor on the left side of the equation is equal to 0, the entire expression will be equal to 0.

2x + 3 = 0

x - 4 = 0

Solve for x.

x = -3/2

x = 4

Use each root to create test intervals.

The solution consists of all of the true intervals.

[tex]-\frac{3}{2}[/tex] < x or x > 4

good luck, i hope this helps :)

someone pls answer this i’ll mark u as brainleist.

Answers

Five miles of running would mean it’d take 30 minutes

la diferencia entre un numero y ocho​

Answers

Answer:

hzyuzj ahuaaia hs7w8aijw. hu7sisj. shususijs bhsusj

Answer:

lo siento, no lo sé

Step-by-step explanation:

What is the end behavior of the graph of the polynomial function y = 10x9 – 4x?

Answers

Answer:

The value of the highest degree ( x^9) is 9 - odd.

So this well rise from negative infinity on the left and rise to positive infinity on the right - or, putting it in a different way, fall to the left and rise to the right.

Answer:

Step-by-step explanation:

1) Trés empresas devem ser contratadas para realizar quatro trabalhos distintos em um condominio. Cada
trabalho será atribuido a uma única empresa e todas elas devem ser contratadas. De quantas maneiras distintas
podem ser distribuidos os trabalhos?
b) 18
C) 36
d) 72
a) 12
e) 108​

Answers

Eu faço a mínima ideia fico

Answer:

la respuesta es la letra B amigo mio

Find the difference.
34(3x+6)−14(5x−24)
I need help

Answers

Answer:

I believe the answer is 32x+24 correct me if im wrong

Step-by-step explanation:

The answer is 32x+540. Let me know if you need an explanation
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