If a distribution has a mean of 25 and a standard deviation of 2, what value would be −4 standard deviations from the mean?

Which formula should be used to find the area of a trapezoid

yawa3891 [41]

You have the correct chosen

4 0

3 years ago

A company sells widgets. The amount of profit, y, made by the company, is related to the selling price of each widget, x, by the

Alex17521 [72]

The equation is that of a parabola, meaning that the maximum (or sometimes minimum) is 1/2 the sum of the solutions found using the quadratic equation.

y = 0 for the 2 solutions to {-b +/- sqrt[b2 - 4ac]} / 2a, where a = -3, b = 152 and c = -1150 from the equation for y. Plug a, b and c into the quadratic formula to get x = 9.2571 and x = 41.4095 as the 2 solutions.

9.2571 + 41.4095 = 50.6666... and the midpoint is 25.3333...

When x = 25.3333..., y = 775.33333.....

To the nearest cent, x=25.33 results in a profit of 775.33.

When x=25.25, Y = 775.31

When x=25.4, Y = 775.32

These are both less than 775.33 when x = 25.33.

3 0

3 years ago

Mrs.Cox is baking a ham for dinner. It takes 1 hour and 30 minutes to bake. The family eats at 6:15 p.m. What time should Mrs.Co

Brilliant_brown [7]

4:85 is the answer because if u subtract 1 hour and 30 minutes

4 0

3 years ago

Teacl Smolts are young salmon at a stage when their skin becomes covered with silvery scales and they start to migrate from fres

erma4kov [3.2K]

Answer:

a) s = 8.81

b) Q1 = 43.4, Q2 = 49.4, Q3 = 57.35

c) See below

Step-by-step explanation:

(a) Find the standard deviation of the reflectance for these smolts. (Round your answer to two decimal places.)

In order to find the standard deviation, we need the mean first. The mean is defined as

$\bar x=\displaystyle\frac{\displaystyle\sum_{i=1}^{n}x_i}{n}$

where the $x_i$ are the values of the data collected and n=50 the size of the sample.

So, the mean is

$\bar x=50.882$

Now, the standard deviation of the sample is defined as

$s=\sqrt{\displaystyle\frac{\displaystyle\sum_{i=1}^n(x_i-\bar x)^2}{n-1}}$

and we have that our standard deviation is

s = 8.81

(b) Find the quartiles of the reflectance for these smolts

To find the quartiles, we must sort the data from lowest to largest:

33.6, 37.7, 38.3, 38.7, 42, 42, 42.2, 42.4, 42.7, 42.8, 42.9, 43.1, 43.7, 43.8, 44.2, 44.6, 45.5, 45.7, 46.3, 46.6, 47.4, 47.6, 47.7, 47.9, 49.2, 49.6, 50.5, 50.9, 51.3, 53, 53.9, 54.8, 54.9, 55.5, 56, 56, 56.2, 57.1, 57.6, 58.3, 59, 59.5, 60.4, 63.2, 63.4, 63.5, 64.6, 68, 69.1, 69.2

The <em>first quartile</em> is the number between the 12th and the 13th data (so 25% of the data are below it and 75% above it)

So the 1st quartile is

$Q_1=\displaystyle\frac{43.1+43.7}{2}=43.4$

The <em>2nd quartile is the median</em>, the point between the 25th and 26th data, it splits the data in two halves.

$Q_2=\displaystyle\frac{49.2+49.6}{2}=49.4$

The 3rd quartile is the point between the 38th and 39th data (so 75% of the data are below it and 25% above it)

$Q_3=\displaystyle\frac{57.1+57.6}{2}=57.35$

(c) Do you prefer the standard deviation or the quartiles as a measure of spread for these data? Give reasons for your preference.

In this case, we prefer the quartiles as a measure of spread since the data are very scattered around the mean and there is no a central tendency.

3 0

3 years ago

8 Skittles come in colors of red, orange, green, purple, and yellow. A snack size bag of skittles has 4 red candies out of a tot

k0ka [10]

Answer: 73

Step-by-step explanation:

You use the bowtie method to get the answer for this problem. This is where you do 4/15 and x/273. You multiply 4 by 273 and x by 15. Resulting in the answers 1092 and 15x. To find the value of x, you divide 1092 by 15. and get 72.8. I rounded up to 73.

5 0

3 years ago