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ANEK [815]
4 years ago
6

What is the mean number of hours that high school students spend on homework per week? It is known that the standard deviation o

f the population is 2.2 hours. In a random sample of 40 students, it is found that they average 13 hours per week on homework.
a) What is the standard deviation for this sample?
b) What is the critical value for a 90% confidence interval?
c) What is the critical value for a 95% confidence interval?
Mathematics
1 answer:
viva [34]4 years ago
6 0
This may help you

it is given that the standard deviation  0.8, so we can use  the normal distribution critical value for the 95% confidence interval. 
<span>sample mean = 2.36 </span>
<span>standard deviation = 0.8 </span>
<span>standard error of mean = σ / √ n </span>
<span>standard error of mean = 0.8 / √ 50 </span>
<span>se = 0.8/7.0711 </span>
<span>standard error of mean 0.1131 </span>
<span>Confidence interval 2.36-(0.1131)(1.96) </span>
<span>and 2.36+(0.1131)(1.96) </span>
<span>95% confidence interval :(2.14, 2.58) </span>
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MakcuM [25]

Answer:

¿en qué periodos  le tocará participar?

El equipo cuatro participa en el periodo 5 - 11 - 17

¿Todos los equipos participarán el mismo  número de veces?

Todos los equipos los hacen 3 veces . menos 1 equipo que lo hace 2 veces

¿Por qué?

Cuatrimestre. =  120 dias

Numero de semanas = 120/ 7  17,1

17 semanas completas 3 dias

No se trabaja la primera semana. por lo que quedan 16 semana 3 dias.

Son 6 equipos para participar todos serian por lo menos 17 semanas 1 dia.

Step-by-step explanation:

Cuatrimestre. =  120 dias

Numero de semanas = 120/ 7  17,1

17 semanas completas 3 dias

No se trabaja la primera semana. por lo que quedan 16 semana 3 dias.

Son seis equipos.   17 ( 16,3) semanas / 6

Todos los equipos los hacen 3 veces . menos 1 equipo que lo hace 2 veces

Semana 1 2 3 4 5 6

Equipos

1        

2  X      

3   X    

4    X    

5     X  

6      X  

7       X

8  X      

9   X    

10    X    

11     X  

12      X  

13       X

14  X      

15   X    

16    X    

17     X  

18      X  

3 0
3 years ago
kala is a software salesmen. her salary is $2400, and she makes an additional $80 for every copy of english is fun she sells. le
andrew11 [14]

P = 2400 + 80N

Total pay if 24 copies:

P = 2400 + 80N

N equals 24

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Total pay = $4,320

6 0
3 years ago
Each year, more than 2 million people in the United States become infected with bacteria that are resistant to antibiotics. In p
Olegator [25]

Answer:

Reject <em>H</em>₀. There is a significant difference in drug resistance between the two states.

Step-by-step explanation:

In this case we need to determine whether the data suggest a statistically significant difference between the proportions of drug-resistant cases in the two states.

The significance level of the test is, <em>α</em> = 0.02.

(1)

The hypothesis can be defined as follows:  

<em>H</em>₀: There is no difference between the proportions of drug-resistant cases in the two states, i.e. p_{1} - p_{2}=  0.  

<em>Hₐ</em>: There is a statistically significant difference between the proportions of drug-resistant cases in the two states, i.e. p_{1} - p_{2}\neq  0.  

(2)

Compute the sample proportions and total proportion as follows:

\hat p_{1}=\frac{12}{189}=0.063\\\\\hat p_{2}=\frac{8}{429}=0.019\\\\\hat p=\frac{12+8}{189+429}=0.032\\

Compute the test statistic value as follows:

Z=\frac{\hat p_{1}-\hat p_{2}}{\sqrt{\hat p(1-\hat p)\times [\frac{1}{n_{1}}+\frac{1}{n_{2}}]}}

   =\frac{0.063-0.019}{\sqrt{0.032(1-0.032)\times [\frac{1}{189}+\frac{1}{429}]}}\\\\=2.86

The test statistic value is 2.86.

(3)

The decision rule is:

The null hypothesis will be rejected if the p-value of the test is less than the significance level.

Compute the p-value as follows:

p-value=2\cdot P(Z>2.86)=2\times 0.00212=0.00424

<em>p</em>-value = 0.00424 < <em>α</em> = 0.02.

The null hypothesis will be rejected at 0.02 significance level.

Reject <em>H</em>₀. There is a significant difference in drug resistance between the two states.

7 0
3 years ago
UNSER
Neko [114]

Answer:

2100

Step-by-step explanation:

30%×3000=900.

3000-900=2100

6 0
3 years ago
What fraction of 2 minutes is 6<br>seconds?​
Inga [223]

Answer:

1/20 of 2 minutes = 6 seconds

5 0
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