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3 years ago

HELPPP ME PLSSSS I NEED THIS FOR MY CLASS

Mathematics

1 answer:

Wewaii [24]3 years ago

7 0

Answer:

hii im looking at the same thing you just have to do the multiplication on that

Step-by-step explanation:

You might be interested in

The combined area of a square and a rectangle is 225 square yards. the length of the rectangle is 8 times the width of the recta

snow_lady [41]

Answer:

The rectangle: L = 40 yards. W = 5 yards

The square: The length and width are both 5 yards.

Step-by-step explanation:

Let L and W be the length and width of the rectangle.

Let l and w be the length and width of the square.

Area for each is:

Rectangle: L*W

Square: l*w

We are told that L*W + l*w = 225 yards^2

We are also told that

L = 8W

and that

l = W

Since the sides of a square are all equal, w is also W: w=W

Summarizing and substituting:

L*W + l*w = 225 yards^2

(8W)*W + W*W = 225 yards^2

8W^2 + W^2 = 225 yards^2

9W^2 = 225 yards^2

W^2 = 25

W = 5 feet

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

Therefore, since L = 8W , L = 40 yards. W = 5 yards for the rectangle.

The square: l=W, so l = 5 yards, and thus w=5 yards

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

Check:

Do a rectangle of 40' x 5' plus a square of 5' x 5' have a total combined area of 225 yards^2?

40yd x 5yd + 5yd x 5yd = 225 yards^2?

200 yd^2 + 25 yd^2 = 225 yards^2?

YES

5 0

2 years ago

The manager of a grocery store has selected a random sample of 100 customers. The average length of time it took these 100 custo

SSSSS [86.1K]

Answer:

The 95% confidence interval would be given by (2.804;3.196)

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".

$\bar X=3.0$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=1$ represent the population standard deviation

n=100 represent the sample size

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

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

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that $z_{\alpha/2}=1.96$