Help me please it’s really hard for me

Of the 240 sandwiches Joanna makes 20% are tuna sandwiches and 40% are jam sandwiches, and the rest are egg salad sandwiches.How

nikitadnepr [17]

240 = 100%
so 10% = 24 sandwiches
all - (tuna) - (jam) = egg
100% - 20% - 40% = 40%
40% = 10%*4
40% = 24*4 = 96

the answer is 96 egg salad sandwiches

4 0

3 years ago

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

3 years ago

Over the summer, Delilah collected 75 books from her personal library that she had outgrown. She decided to donate them to the m

shepuryov [24]

Answer:

she donated 9 books to hers

3 0

3 years ago

Read 2 more answers

Can someone help me please!!

ratelena [41]

The coordinates of E are (5.75, 0).

<h3>What is midpoint?</h3>

The midpoint is the middle point of a line segment. It is equidistant from both endpoints, and it is the centroid both of the segment and of the endpoints.

Given that, C is the midpoint of AB, D is the midpoint of CB and E is the midpoint of DB.

Formula for coordinates of midpoint,

(x, y) = [(x1+x2)/2, (y1+y2)/2]

Coordinates of C;

(x, y) = (-10+8)/2, (14-2)/2

(x, y) = (-1, 6)

Coordinates of D;

(x, y) = (-1+8)/2, (6-2)/2

(x, y) = (3.5, 2)

Coordinates of E;

(x, y) = (3.5+8)/2, (2-2)/2

(x, y) = (5.75, 0)

Hence, The coordinates of E are (5.75, 0).

For more references on midpoints, click;

brainly.com/question/28224145

#SPJ1

8 0

1 year ago

What is the length of the base of a right triangle with an area of 20 square meters and a height of 4 meters? 5 m 10 m 80 m 160

o-na [289]

You find the area of a triangle by using 1/2*b*h where b is the base and h is the height. since we already know the area is 20 and the height is for you plus them in so the problem would be 20= 1/2 (b) (4) then you multiply what you know together to get 20= 2b and then isolate the b by dividing both sides by two so the base should be 10 m

8 0

3 years ago

Read 2 more answers