Before the summer season begins, you need to decide how many postcards to stock in your shop. Historically, the number of postcards you sell during the summer season has approximately a normal distribution with mean 50 and standard deviation 7 (in thousands of postcards). If you want to be approximately 80% sure that you can meet demand, how many postcards should you stock

You should stock 59 thousands of postcards

Step-by-step explanation:

In the standard normal distribution table, you want to find the Z with probability 0.4, which is (see figure attached) 1.28. Z is calculated as follows:

Z = (x - μ)/σ

where μ is the mean and σ is the standard deviation. Replacing with data:

1.28 = (x - 50)/7

x = 1.28*7 + 50 = 59 thousands of postcards

So, approximately 80% of the demand would be satisfied with a number of postcards between 41000 and 59000 (notice the curve is symmetrical).

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.

i think it's ф or x=6,-6

step-by-step explanation:

-x^2=-36

x^2=-36

ф

or

if you mean by : -(x^2)=-36

it'll be: x^2=36

x=6,x=-6

hope it'll ! have a good day!

you for asking!