A population increased 13% up to 2,877. What was the population before the increase?

Find the result when 90 is decreased by 35%. 58.5 75.6 60.5 78.5

avanturin [10]

In this question, it's asking you to find the number when 90 is subtracted by 35%. So, you find 35% of 90 which is 31.5 and you minus it from 90 = 58.5.

> 90 x 35% = 31.5
> 90 - 31.5 = 58.5

3 0

4 years ago

A random sample of size n1= 25, taken from a normal population with a standard deviation σ1= 5, has a mean X1= 80. A second rand

sesenic [268]

Answer:

The 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

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".

$\bar X_1 =80$ represent the sample mean 1

$\bar X_2 =75$ represent the sample mean 2

n1=25 represent the sample 1 size

n2=36 represent the sample 2 size

$\sigma_1 =5$ sample standard deviation for sample 1

$\sigma_2 =3$ sample standard deviation for sample 2

$\mu_1 -\mu_2$ parameter of interest.

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$ (1)

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =80-75=5$

Since the Confidence is 0.94 or 94%, the value of $\alpha=0.06$ and $\alpha/2 =0.03$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.03,0,1)".And we see that $z_{\alpha/2}=1.88$

The standard error is given by the following formula:

$SE=\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$

And replacing we have:

$SE=\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=1.118$

Confidence interval

Now we have everything in order to replace into formula (1):

$5-1.88\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=2.898$

$5+1.8\sqrt{\frac{6^2}{36}+\frac{7^}{49}}=7.102$

So on this case the 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

7 0

3 years ago

Rate my art HONESTLY

telo118 [61]

I would say avoid adding any more detail to the eyes and facial features. normally pointillism uses alot more dots and makes them most concentrated in darker areas. i would recommend trying to add shadows to most of it or adding more detail to the hat. Ii think her neck looks ok but there isn't really a way to get rid of the diagonal that you made.

4 0

1 year ago

Read 2 more answers

Five and one third times twenty eight

hoa [83]

149.333333333... is your answer

3 0

3 years ago

Read 2 more answers

Customers at the Palace Pro Shop receive a 10% discount if they are members. All customers must pay 7% in sales tax. The functio

11111nata11111 [884]

Answer:

The total amount a member pays for an item with a regular price of x dollars is T (x) = 0.963x.

Step-by-step explanation:

Key points:

Discount is subtracted from the regular price of an item.
Sales tax is added to the regular price of an item.

It is provided that the customers receive a 10% discount if they are members and all customers must pay 7% in sales tax.

Two functions are provided are:

f (x) = 0.90x ; the price of an item after the 10% member discount

g (x) = 1.07x ; the total amount customers pay for a purchase after sales tax is applied.

Compute the total amount a member pays for an item with a regular price of x dollars as follows:

T (x) = Discount × Sales Tax

= 0.90 × 1.07 × x

= 0.963x.

Thus, the total amount a member pays for an item with a regular price of x dollars is T (x) = 0.963x.

3 0

3 years ago