What multiplys to 3 adds to 6

A cognitive psychologist wants to investigate whether memory for a shopping list is affected by the strategy used to study the l

Orlov [11]

Answer:

There is no sufficient evidence

Step-by-step explanation:

See attached files

7 0

3 years ago

State University uses thousands of fluorescent light bulbs each year. The brand of bulb it currently uses has a mean life of 600

Ipatiy [6.2K]

Answer:

The test statistic is t = 2.5.

The p-value of the test is of 0.007 < 0.05, which means that the evidence supports the manufacturer's claim at the .05 significance level.

Step-by-step explanation:

Mean life of 600 hours. Test if it is more.

At the null hypothesis, we test if the mean is of 600 hours, that is:

$H_0: \mu = 600$

At the alternative hypothesis, we test if the mean is of more than 600 hours, that is:

$H_1: \mu > 600$

The test statistic is:

$t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, s is the standard deviation and n is the size of the sample.

600 is tested at the null hypothesis:

This means that $\mu = 600$

Suppose 100 bulbs were tested and found to have a mean of 625 hours with a standard deviation of 100.

This means that $n = 100, X = 625, s = 100$ .

Value of the test-statistic:

$t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}$

$t = \frac{625 - 600}{\frac{100}{\sqrt{100}}}$

$t = 2.5$

The test statistic is t = 2.5.

P-value of the test and decision:

The p-value of the test is the probability of finding a sample mean above 625 hours, which is a right-tailed test, with t = 2.5 and 100 - 1 = 99 degrees of freedom.

Using a t-distribution calculator, this p-value is of 0.007.

The p-value of the test is of 0.007 < 0.05, which means that the evidence supports the manufacturer's claim at the .05 significance level.

4 0

3 years ago

Assume that when Human Resource managers are randomly selected, 62% say job applicants should follow up within two weeks. If 25

stellarik [79]

Using the binomial distribution, it is found that there is a 0.1008 = 10.08% probability that exactly 18 of them say job applicants should follow up within two weeks.

<h3>What is the binomial distribution formula?</h3>

The formula is:

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$C_{n,x} = \frac{n!}{x!(n-x)!}$

The parameters are:

x is the number of successes.

n is the number of trials.

p is the probability of a success on a single trial.

The values of the parameters are given as follows:

n = 25, p = 0.62.

The probability that exactly 18 of them say job applicants should follow up within two weeks is P(X = 18), hence:

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 18) = C_{25,18}.(0.62)^{18}.(0.38)^{7} = 0.1008$

0.1008 = 10.08% probability that exactly 18 of them say job applicants should follow up within two weeks.

More can be learned about the binomial distribution at brainly.com/question/24863377

#SPJ1

6 0

2 years ago

which of the following correctly gives the center and radius of the circle defined by the equation (z-7)^2 = 10?

ANEK [815]

Answer:

Center (7,2); Radius - Square Root of 10

Step-by-step explanation:

Equation for a Cricle:

(x−h)^2 + (y−k)^2 = r^2

Where:

h = x-coordinate of the center of the circle

k = y-coordinate of the center of the circle

r = radius of the circle

For this problem, your h = 7, k = 2, and r = square root of 10

5 0

3 years ago

Find the missing measurements for the rectangle when the area equals 216 and the perimeter equals 66

kirill [66]

$\bf \stackrel{\textit{perimeter of a rectangle}}{P=2(L+w)}~~ \begin{cases} L=length\\ w=width\\ \cline{1-1} P=66 \end{cases}\implies 66=2(L+w) \\\\\\ 33=L+w\implies \boxed{33-w=L} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{area of a rectangle}}{A=Lw}\qquad \implies 216=Lw\implies 216=(33-w)w \\\\\\ 216=33w-w^2\implies w^2-33w+216=0 \\\\\\ (w-24)(w-9)=0\implies w= \begin{cases} 24\\ 9 \end{cases}$

now, both values are valid, so if "w" is either one, "L" is the other.

8 0

3 years ago