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3 years ago

Who can help me with this I’ll mark u as brainliest

Mathematics

2 answers:

Vikentia [17]3 years ago

5 0

Answer:

The answer is D

Step-by-step explanation:

Crown me?

grandymaker [24]3 years ago

4 0

Answer:

Step-by-step explanation:

x^2+18x-19=0

(x+18)(x-1)

x=-18

x=1

You might be interested in

A snail climbs to the top of a coconut tree 18 meters high. In an hour it will climb 2 meters. But if it go 2 meters, it will sl

kumpel [21]

Answer:

The snail will reach the top of the coconut in 18 hours.

Step-by-step explanation:

If the snail will climb 2 meters in 1 hour but it will slip down one meter for every 2 meters climbed, then the distance traveled will be:

$d = 2 m - 1 m = 1 m$

Since in 1 hour, it climbs 2 meters minus 1 meter, the time in which the snail will reach the top is:

$t = \frac{1 h}{1 m}*18 m = 18 h$

Therefore, the snail will reach the top of the coconut in 18 hours.

I hope it helps you!

5 0

3 years ago

How do you solve 28-2.2x=11.6x-54.8??

malfutka [58]

28 - 2.2x = 11.6x - 54.8
28 + 54.8 = 11.6x + 2.2x
82.8 = 13.8x
82.8 / 13.8 = x
6 = x
or x = 6

6 0

3 years ago

The proprietor of a boutique in New York wanted to determine the average age of his customers. A random sample of 25 customers r

jolli1 [7]

Answer:

$28-2.064\frac{10}{\sqrt{25}}=23.872$

$28+2.064\frac{10}{\sqrt{25}}=32.128$

So on this case the 95% confidence interval would be given by (23.9;32.1)

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".

$\bar X=28$ represent the sample mean

$\mu$ population mean (variable of interest)

s=10 represent the sample standard deviation

n=25 represent the sample size

Solution to the problem

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

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

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=25-1=24$

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: "=-T.INV(0.025,24)".And we see that $t_{\alpha/2}=2.064$