When solving an equation, Anne's first step is shown below. Which property justifies Anne's first step?

PLEASE HELP FAST <br><br>WILL MARK BRAINLIST

liq [111]

Answer:

1, (c) 2,(c) 3,(a)

Step-by-step explanation:

1, f (x) = 2-x and f(2) = 2-2

for example f(-4) = 2-(-2) = 0

=4

3, 120° - 60° = 60

5 0

2 years ago

A local trucking company fitted a regression to relate the travel time (days) of its shipments as a function of the distance tra

Karo-lina-s [1.5K]

Answer:

The critical values for α = 0.10 are t=±1.7341.

Step-by-step explanation:

The critical values for a two tailed test are the values of t that are placed in the limit of the significance level. If the test statistic t is greater than this critical values, the null hypothesis is rejected.

To determine this values, we first divide the significance level by 2. With a t-table or app, we can determine the t values for P(x>|t|)=α/2=0.05.

In this case, for a degrees of freedom DF=20-2=18, we have the test statistic t=±1.7341 that satisfies the condition.

Solution of the hypothesis test

In this problem we want to prove if the slope of the regression model is different from 0, by means of a hypothesis test.

First, we state the null and alternative hypothesis:

$H_0: B_1=0\\\\H_1: B_1 \neq 0$

The significance level is $\alpha=0.10$ .

The degrees of freedom for a simple regression model is:

$DF=n-2=20-2=18$

The standard error estimated of the slope is 0.0053.

The test statistic t is calculated as:

$t=\frac{B_1}{SE}=\frac{0.0214}{0.0053} = 4.0377$

The P-value for a two-tailed test for a t=4.0377 and DF=18 is:

$P=0.00078$

The P-value is smaller than the significance level, so the effect is statistically significant. The null hypothesis is rejected.

7 0

3 years ago

Presbycusis is the gradual hearing loss that occurs as a person ages. An estimated one-quarter of Americans between the ages of

svetlana [45]

Answer:

The answer is the "Null hypothesis and Alternative hypothesis".

Step-by-step explanation:

The null hypothesis is almost like a hypothesis test, which indicates the certain demographic characteristics which aren't varied.

The alternative presumption will be that the hypothesis besides making predictions is opposite to the void assumption. Its posts are generally taken as a result of a meaningful effect.

Difference:

The null hypothesis is indeed a gross generalization, which specifies there is no relation between different phenomenons under evaluation. There is no association between the two groups. An alternate solution hypothesis is a statement, that defines there is a relation between different chosen variables in this study.

3 0

2 years ago

Using the key below, classify each of the following descriptions of epidemiologicalstudies according to study type. In your answ

emmasim [6.3K]

Answer:

Answers are written in BOLD in the explanation below.

Step-by-step explanation:

(A) The study was done in 1975 but the 825 insulation workers were employed or worked between 1941 and 1944. This makes the study a RETROSPECTIVE study.

There is an exposed group (insulation workers) and an unexposed group (coworkers who did not work with insulation). In addition (an additional reason), the study begins with exposed patients and then unexposed patients. These reasons make it a COHORT study.

This study is also an ANALYTICAL study, as the investigators made a postulation, based on analysis of the number of lung cancer deaths among non-insulation workers and the number of lung cancer deaths among insulation workers.

This is also an ECOLOGICAL study, as study results are applicable only at population level.

(B) This is an EXPERIMENTAL study, as the researcher/investigator seeks new knowledge by selecting groups to derive certain data from; in a step by step manner.

Due to the random selection of subjects (volunteers) and random assignment of them to the two groups, this is a RANDOMIZED TRIAL.

The presence of similar experimental and control groups (all volunteers/subjects have osteoarthritis) is a key feature of RANDOMIZED CONTROLLED TRIAL.

After the selection of subjects, experiment of pain levels was conducted for some months (up to a year). This makes the study a PROSPECTIVE study because there was follow-up on the groups, to see who develops the outcome of interest.

The fact that there was no experimental report after 9 and 12 months of follow-up is another key feature of the RCT because in a RCT, the investigator often faces issues like dropout and noncompliance of subjects.

(C) This is a COMMUNITY TRIAL study because two cities/communities are experimented on.

This is also an EXPERIMENTAL study. The fact that both cities have similar demographic profiles and air pollution levels confirms a key feature of experimental studies. There is a 2-year follow-up. This is another reason why the study is experimental and PROSPECTIVE.

(D) This is an OBSERVATIONAL study. This is because already available data was collected and simply looked upon or observed, to know if chewing tobacco was a significant risk factor for stomach cancer.

The data is historical data, hence this is a RETROSPECTIVE study.

This is also a CROSS-SECTIONAL study because it is observational in nature and it gives characteristics of subjects at a single point in time, not over a period of time. It does not have a follow-up period and cannot provide cause-effect relationship between variables.

GOODLUCK!

4 0

3 years ago

While playing a trivia game Adam answer eight questions correct in the first half and two questions correct in the second half i

ratelena [41]

Answer:

80 points

Step-by-step explanation:

First Half: Second Half: Total Right Answers

8 questions right + 2 questions right = 10 questions right

10*8 points a piece = 80 points

3 0

2 years ago