Find the highest common factor of 126 and 140 Please help

A college student is interested in investigating the TV-watching habits of her classmates and surveys 20 people on the number of

Alla [95]

Answer:

80% confidence interval of the true average number of hours of TV watched per week is [8.28 hours, 11.02 hours].

Step-by-step explanation:

We are given that a college student is interested in investigating the TV-watching habits of her classmates and surveys 20 people on the number of hours they watch per week. The results are provided below;

Hours of TV per week (X): 6, 14, 13, 6, 16, 10, 19, 4, 5, 5, 18, 8, 7, 14, 8, 8, 9, 12, 6, 5.

Firstly, the Pivotal quantity for 80% confidence interval for the true average is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean number of hours of TV watched per week = $\frac{\sum X}{n}$ = 9.65

s = sample standard deviation = $\sqrt{\frac{\sum (X -\bar X)^{2} }{n-1} }$ = 4.61

n = sample of people = 20

$\mu$ = true average number of hours of TV watched per week

Here for constructing 80% confidence interval we have used One-sample t-test statistics as we don't know about population standard deviation.

So, 80% confidence interval for the true average, $\mu$ is ;

P(-1.33 < $t_1_9$ < 1.33) = 0.80 {As the critical value of t at 19 degrees of

freedom are -1.33 & 1.33 with P = 10%}

P(-1.33 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.33) = 0.80

P( $-1.33 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.33 \times {\frac{s}{\sqrt{n} } }$ ) = 0.80

P( $\bar X-1.33 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.33 \times {\frac{s}{\sqrt{n} } }$ ) = 0.80

80% confidence interval for $\mu$ = [ $\bar X-1.33 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.33 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $9.65-1.33 \times {\frac{4.61}{\sqrt{20} } }$ , $9.65+1.33 \times {\frac{4.61}{\sqrt{20} } }$ ]

= [8.28 hours, 11.02 hours]

Therefore, 80% confidence interval of the true average number of hours of TV watched per week is [8.28 hours, 11.02 hours].

7 0

3 years ago

A college student is taking two courses. The probability she passes the first course is 0.67. The probability she passes the sec

andrezito [222]

Answer:

0.58 = 58% probability she passes both courses

Step-by-step explanation:

We can solve this question treating the probabilities as a Venn set.

I am going to say that:

Event A: She passes the first course.

Event B: She passes the second course.

The probability she passes the first course is 0.67.

This means that $P(A) = 0.67$

The probability she passes the second course is 0.7.

This means that $P(B) = 0.7$

The probability she passes at least one of the courses is 0.79.

This means that $P(A \cup B) = 0.79$

a. What is the probability she passes both courses

This is $P(A \cap B)$ .

We use the following relation:

$P(A \cup B) = P(A) + P(B) - P(A \cap B)$

So

$P(A \cap B) = P(A) + P(B) - P(A \cup B) = 0.67 + 0.7 - 0.79 = 0.58$

0.58 = 58% probability she passes both courses

5 0

3 years ago

Whats 78 × 4 × 56 × 7 ×2 This is random just for fun:)

Dafna11 [192]

Answer: 244608

Step-by-step explanation: Multiply all of the numbers!

8 0

3 years ago

Read 2 more answers

What is the value of x?

eimsori [14]

Answer:

16.1

Step-by-step explanation:

7 0

3 years ago

Mr. Kelly and mr. Sully each make some new units for geometry. Total they need to make 12 units.

DaniilM [7]

Answer:

What exactly do you need to be answered?

Step-by-step explanation:

3 0

3 years ago