Which of the following is equal to 7 1/4?

What is 0.000285 expressed in scientific notation

kow [346]

Answer: the answer is 2.85 x 10^-4

Step-by-step explanation:

or u can just look up Mathway and that will give you the answer and a much quicker way too https

6 0

2 years ago

You want to test your newly created Web site, so you have 250 people access it from random locations at random times. Of the peo

Arte-miy333 [17]

Answer: 505

Step-by-step explanation:

The formula to find the sample size n , if the prior estimate of the population proportion (p) is known:

$n= p(1-p)(\dfrac{z}{E})^2$ , where E= margin of error and z = Critical z-value.

Let p be the population proportion of crashes.

Prior sample size = 250

No. of people experience computer crashes = 75

Prior proportion of crashes $p=\dfrac{75}{250}=0.3$

E= 0.04

From z-table , the z-value corresponding to 95% confidence interval = z=1.96

Required sample size will be :

$n=0.3(1-0.3)(\dfrac{1.96}{0.04})^2$ (Substitute all the values in the above formula)

$n= (0.21)(49)^2= 0.21\times2401$

$n= 504.21\approx505$ (Rounded to the next integer.)

∴ Required sample size = 505

6 0

3 years ago

94 1/4 divided by 7 1/4

Lerok [7]

The answer is 13 :)))

6 0

3 years ago

Read 2 more answers

Which pair of numbers have a greatest common factor of 7?

ella [17]

<span>The GCF is the number that is a factor of both (or all) of the numbers of a given set and which is the biggest factor of this kind (often the smaller number of the two)

7 and 14 have a greatest common factor of 7.

28 and 7 also have a GCF of 7, so the first two responses fit.

21 and 3 have a GCF of 3, so that isn't correct.

7 and 1 have a GCF of 1, so that's incorrect as well.</span>

3 0

3 years ago

Read 2 more answers

Day care centers expose children to a wider variety of germs than the children would be exposed to if they stayed at home more o

Ostrovityanka [42]

Answer:

a) The study is an observational study

b) The proportion of children with significant social activity in children with acute lymphoblastic leukemia is approximately 0.802

The proportion of children with significant social activity in children without acute lymphoblastic leukemia is approximately 0.8565

c) The odds ratio is approximately 0.6780

d) The 95% CI is approximately 0.523 < OR < 0.833

e) i) Yes

ii) Children with more social activity have a higher occurrence of acute lymphoblastic leukemia

Step-by-step explanation:

a) An experimental study is a study in which the researcher adds inputs to the study and then monitors the outcomes

An observational study is one in which the researcher observes risk factors and does not intervene in the process

Therefore, the study is an observational study

b) The proportion of children with significant social activity in children with acute lymphoblastic leukemia is $\hat p_1$ = 1020/1272 = 85/106 = $0.8\overline {0188679245283}$ ≈ 0.802

The proportion of children with significant social activity in children without acute lymphoblastic leukemia is $\hat p_2$ = 5343/6238 ≈ 0.8565

c) We have the following two way table;

$\begin{array}{ccc}Lymphoblastic \ Leukemia &With \ Social \ Activity & Without \ Social \ Activity\\With&1020 \ (a)&252 \ (b)\\Without&5343 \ (c)&895 \ (d) \end{array}$

$The \ odds \ ratio = \dfrac{1,020 \times 895}{5,343 \times 252} \approx 0.6780$

The odds ratio ≈ 0.6780

d) The 95% confidence interval for the odds ratio is given as follows;

$95 \% \ CI = OR \ \pm \ 1.96 \times \sqrt{\dfrac{1}{a} +\dfrac{1}{b}+\dfrac{1}{c}+\dfrac{1}{d}}$

Where;

a = 1020, b = 252, c = 5343, d = 895

Therefore;

$95 \% \ CI \approx 0.6780 \ \pm \ 1.96 \times \sqrt{\dfrac{1}{1,020} +\dfrac{1}{252}+\dfrac{1}{5,343}+\dfrac{1}{895}} \approx 0.678 \pm0.155$

The 95% CI ≈ 0.523 < OR < 0.833

e) i) Given that the observed Odds Ratio is within the Confidence Interval, therefore, there is an indication that the amount of social activity is associated with acute lymphoblastic leukemia

ii) Based on the proportion of the study findings, children with more social activity have a higher occurrence of acute lymphoblastic leukemia

6 0

2 years ago