Plss help im bad at math:v 100 points!

The estimated daily living costs for an executive traveling to various major cities follow. The estimates include a single room

Alexandra [31]

Answer:

$\bar x = 260.1615$

$\sigma = 70.69$

The confidence interval of standard deviation is: $53.76$ to $103.25$

Step-by-step explanation:

Given

$n =20$

See attachment for the formatted data

Solving (a): The mean

This is calculated as:

$\bar x = \frac{\sum x}{n}$

So, we have:

$\bar x = \frac{242.87 +212.00 +260.93 +284.08 +194.19 +139.16 +260.76 +436.72 +355.36 +.....+250.61}{20}$

$\bar x = \frac{5203.23}{20}$

$\bar x = 260.1615$

$\bar x = 260.16$

Solving (b): The standard deviation

This is calculated as:

$\sigma = \sqrt{\frac{\sum(x - \bar x)^2}{n-1}}$

$\sigma = \sqrt{\frac{(242.87 - 260.1615)^2 +(212.00- 260.1615)^2+(260.93- 260.1615)^2+(284.08- 260.1615)^2+.....+(250.61- 260.1615)^2}{20 - 1}}$ $\sigma = \sqrt{\frac{94938.80}{19}}$

$\sigma = \sqrt{4996.78}$

$\sigma = 70.69$ --- approximated

Solving (c): 95% confidence interval of standard deviation

We have:

$c =0.95$

So:

$\alpha = 1 -c$

$\alpha = 1 -0.95$

$\alpha = 0.05$

Calculate the degree of freedom (df)

$df = n -1$

$df = 20 -1$

$df = 19$

Determine the critical value at row $df = 19$ and columns $\frac{\alpha}{2}$ and $1 -\frac{\alpha}{2}$

So, we have:

$X^2_{0.025} = 32.852$ ---- at $\frac{\alpha}{2}$

$X^2_{0.975} = 8.907$ --- at $1 -\frac{\alpha}{2}$

So, the confidence interval of the standard deviation is:

$\sigma * \sqrt{\frac{n - 1}{X^2_{\alpha/2} }$ to $\sigma * \sqrt{\frac{n - 1}{X^2_{1 -\alpha/2} }$

$70.69 * \sqrt{\frac{20 - 1}{32.852}$ to $70.69 * \sqrt{\frac{20 - 1}{8.907}$

$70.69 * \sqrt{\frac{19}{32.852}$ to $70.69 * \sqrt{\frac{19}{8.907}$

$53.76$ to $103.25$

8 0

2 years ago

Please help me... :(

mr_godi [17]

Answer:

6

Step-by-step explanation:

Think of it as a ratio. The recipe calls for 2:3. If Jason used 4, then you need to match the other side.

4/2=2

So you need to multiply 3 by 2 to find the match.

3x2=6

The ratio is 4:6, so Jason uses 6 teaspoons of baking powder.

-hope it helps

4 0

2 years ago

Harriet earns the same amount of money each day. Her gross pay at the end of 7 work days is 35h + 56 dollars. Which expression r

Alex_Xolod [135]

Answer:

Gross pay per days is 5h+8 dollars

Step-by-step explanation:

we are given

total gross pay =35h+56 dollars

total number of days =7

we know that

gross pay per day = ( total gross pay)/(total number of days)

we can plug values

gross pay per day is

$=\frac{35h+56}{7}$

we can simplify it

$=\frac{7(5h+8)}{7}$

$=5h+8$

7 0

3 years ago

Read 2 more answers

In the image below, ABC ~ DEF What is the length of EF and the measure of D

Gwar [14]

If triangle ABC is congruent to triangle DEF, then EF = BC = 27
This is because BC and EF are the last two letters of ABC and DEF respectively. They match up and correspond, being congruent by CPCTC

-------------------------------------------------------------------------------------------------------------

Similarly, if triangle ABC is congruent to triangle DEF, then angle D = angle A = 49 degrees

The letter D and the letter A are the first letters of DEF and ABC respectively. So they match up and are congruent by CPCTC

CPCTC = Corresponding Parts of Congruent Triangles are Congruent

-------------------------------------------------------------------------------------------------------------

So in short, the answer is choice B) 27; 49

7 0

3 years ago

Salvatore attends class every 4 weeks, chess club every 2 weeks, and fencing lessons every 3 weeks. If he attended all three thi

Amiraneli [1.4K]

Answer:

12

Step-by-step explanation:

Listing the weeks he will attend each item

Class 4,8,12,16

Chess 2,4,6,8,10,12

Fencing 3,6,9,12

Starting today at week 0, he will attend all 3 again at week 12

6 0

3 years ago

Read 2 more answers

Plss help im bad at math:v​ 100 points!

Plss help im bad at math:v 100 points!