A hiker descended 320 feet in 40 minutes. Find the hiker's average change in elevation per minute.

A classic rock radio station claims to play an average of 50 minutes of music every hour. However, it seems that every time you

tia_tia [17]

Answer:

a) $47.917-1.796\frac{2.811}{\sqrt{12}}=46.460$

$47.917+1.796\frac{2.811}{\sqrt{12}}=49.374$

b) Null hypothesis: $\mu =50$

Alternative hypothesis: $\mu \neq 50$

And after analyze the interval obtained the upper limit not contains the value of 50, so then we can conclude that the claim is not satisfied for this case, and the population mean seems to be lower than 50 at 10% of significance.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

We have the following data: 44 49 45 51 49 53 49 44 47 50 46 48

And we can calculate the sample mean and deviation with the following formulas:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$s= \frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}$

And replacing we got:

$\bar X= 47.917, s= 2.811$

$\mu$ population mean (variable of interest)

n=12 represent the sample size

Part a: Calculate the confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The degrees of freedom are given:

$df= n-1= 12-1=11$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.05,11)".And we see that $t_{\alpha/2}=1.796$

Now we have everything in order to replace into formula (1):

$47.917-1.796\frac{2.811}{\sqrt{12}}=46.460$

$47.917+1.796\frac{2.811}{\sqrt{12}}=49.374$

Part b

For this case the system of hypothesis are:

Null hypothesis: $\mu =50$

Alternative hypothesis: $\mu \neq 50$

And after analyze the interval obtained the upper limit not contains the value of 50, so then we can conclude that the claim is not satisfied for this case, and the population mean seems to be lower than 50 at 10% of significance.

6 0

3 years ago

What is the slope of the line that passes through the points ( 5 , 6 )and ( 5 , 9 ) ? Write your answer in simplest form.

Lapatulllka [165]

Answer:

3

Step-by-step explanation:

9-6

over

6-5

=3/1

simplify

m=3

8 0

2 years ago

Which decimal is equivalent to 13/11

TiliK225 [7]

Answer:

1.18 is the answer but if u want to round u have the answer as 1.20=1.2

7 0

3 years ago

Read 2 more answers

Find the number of ways to distribute six different toys to three different children such that each child gets at least one toy.

Lisa [10]

Answer:

Step-by-step explanation:

Given that there are six different toys and they are to be distributed to three different children.

The restraint here is each child gets atleast one toy.

Let us consider the situation as this.

Since each child has to get atleast one toy no of ways to distribute

any 3 toys to the three children each. This can be done by selecting 3 toys from 6 in 6C3 ways and distributing in 3! ways

So 3 toys to each one in 6x5x4 =120 ways

Now remaining 3 toys can be given to any child.

Hence remaining 3 toys can be distributed in 3x3x3 =27 ways

Total no of ways

= 120(27)

= 3240

8 0

2 years ago

What is the mean of the data set that is represented by this data plot?

const2013 [10]

Answer:

90

Step-by-step explanation:

4 0

2 years ago

Read 2 more answers