Rewrite the fractions 2/5 and 4/15 as fractions with a least common denominator

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

In which number is the digit 5 one-tenth as much than it is in the number 25,973?

garik1379 [7]

Let's first look at the number that we are given.25,973. We would read this number as eighty-nine and five hundred forty seven thousandths.

In this number, the 5 is in the tenths place. That is equivalent to 5/10 or five tenths (five divided by ten or 0.5).

The questions asks you to write a number in which the digit "5" is one-tenth the value of the number 5 in 25,973

You are looking for a number that is one-tenth of 0.5. Remember, one-tenth equals 1/10 which equals 0.1.

One-tenth of 0.5 equals 0.1 multiplied by 0.5 which equals 0.05. Hence, the number 5 has to be in the hundredths place to answer the question.

Using the number that we were given (89.547), if you multiply 25,973 by (1/10) you get 8.9547.

In the number 8.9547, the digit 5 is one-tenth the value of the number 5 in 25,973

The answer is 8.9547.

I hope this explanation helps.

8 0

3 years ago

Find the slope of the line that contains these points (-2,5) (-4,11)

nevsk [136]

The first thing you have to do is:

subtract: 11-5

Then subtract: -4-(-2)

then you put it as a fraction: 6/-2 or -3

That -3 would be considered the slope.

So now you have: y=-3x+ b

So what you have to do is plug in one of the points into the equation to find out what b is.

For example: 11 = -3(-4) + b
11=12 + b
-12 -12
b = -1
So the answer is: y = -3x -1

3 0

3 years ago

Read 2 more answers

10 points per answer!

Mkey [24]

Answer:

d

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

A dot plot titled Number of Hours Spent on Homework goes from 1 to 6. There is 1 dot above 1, 5 dots above 2, 6 dots above 3, 4