All categories

2 years ago

The average price of a laptop is $965. Assume laptop prices are approximately normally distributed with a standard

Mathematics

1 answer:

miss Akunina [59]2 years ago

6 0

Answer:

$836.8

Step-by-step explanation:

Average price = mean = $965

Standard deviation, = $100

Given that distribution is approximately normal ;

The least expensive 10% of the laptops :

We Obtain the Zscore that corresponds to P(Z ≤ 0.1) ; this means the least 10% of the laptops ;

From, a normal probability distribution table ;

P(Z ≤ 0.1) = - 1.282

We substitute this into the Zscore formula :

Zscore = (x - mean ) / standard deviation

x = price

-1.282 = (x - 965) / 100

-128.2 = (x - 965)

x = - 128.2 + 965

x = $836.8

Hence, price is $836.8

You might be interested in

The measures of the angles In alinear pair are x degree and (x+25) degree. Find the measures of each of them

natta225 [31]

Answer:

77.5° and

102.5°

Step-by-step explanation:

Angles in a linear pair sum up to 180°

Therefore, x + (x +25) = 180

x + x +25 = 180

2x + 25 = 180

2x = 180- 25

2x 155°

dividing bothsides by 2

x = 155/2

x = 77.5

Therefore,

x = 77.5°

(x+25) = 77.5 + 25 = 102.5°

8 0

2 years ago

Two brands of AAA batteries are tested in order to compare their voltage. The data summary can be found below.

garik1379 [7]

Answer:

The 95% confidence interval would be given by $0.281 \leq \mu_1 -\mu_2 \leq 0.529$

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".

$\bar X_1 =9.2$ represent the sample mean 1

$\bar X_2 =8.8$ represent the sample mean 2

n1=27 represent the sample 1 size

n2=30 represent the sample 2 size

$\sigma_1 =0.3$ population standard deviation for sample 1

$\sigma_2 =0.1$ population standard deviation for sample 2

$\mu_1 -\mu_2$ parameter of interest.

Solution to the problem

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:

$\bar X_1 -\bar X_2 =9.2-8.8=0.4$

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 $t_{\alpha/2}=1.96$

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

$0.4-1.96\sqrt{\frac{0.3^2}{27}+\frac{0.1^2}{30}}=0.281$

$0.4+1.96\sqrt{\frac{6^2}{36}+\frac{7^}{49}}=0.519$

So on this case the 95% confidence interval would be given by $0.281 \leq \mu_1 -\mu_2 \leq 0.529$

6 0

3 years ago

What is 3.2 x 10^-8 expressed as a decimal?

aniked [119]

Answer:

3.2MULTIPLY10-8

Step-by-step explanation:BECUASE THERE IS A NEGATIVE SENSE AND WHEN YOU PRESS YOUR CALACULTAOR U WILL SEE IT TRY IT IF DONT UNDERSTAND LET ME KNOW AGAIN THANKS

4 0

3 years ago

What is the answer to y=2/3x+4

In-s [12.5K]

Answer:

y=2 over 3x-4

Step-by-step explanation:

I just know pog

3 0

2 years ago

Evaluate the expression a3 -b/c for a = 3, b = 2 and c = 4. write in simplest form

Scilla [17]

Hello There!

Write out your equation:
$(a^3 - b)/c$
Substitute the values in:
$(3^3 - 2)/4$
Simplify:
$(27 - 2)/4$
$25/4$
Solve:
It is 6.25.

Therefore, your answer is 6 1/4.

Hope This Helps You!
Good Luck :)

- Hannah ❤

6 0

3 years ago