1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ad-work [718]
3 years ago
5

A researcher recruited 55 adults and tested their ability to remember a list of words. For each participant, the researcher coun

ted the number of words correctly recalled and recorded their age (in years).
HYPOTHESIS
The research hypothesis is that age is related to memory performance.
This hypothesis is:__________.
a. directional
b. non-directional
Mathematics
1 answer:
mr Goodwill [35]3 years ago
6 0

Answer:

b. non-directional

Step-by-step explanation:

A directional hypothesis can be described as a hypothesis which predicts the direction of impact, either positive or negative, of one variable, especially independent variable, on the other variable which is known as an independent variable. For example, the hypothesis "age <u>reduces</u> memory performance" is a directional hypothesis. The reason is that "reduces" show the direction that age has a negative effect on memory performance.

On the other hand, non-directional hypothesis can be described as a hypothesis that does not predict the direction of impact but only states the relationship between two variables. For example, the research hypothesis is in the question that "age is <u>related</u> to memory performance" is non-directional hypothesis. This because the word "related" in the hypothesis only indicate that there is a relationship between the two variables, not the direction of effect of one variable on the other.

You might be interested in
Suppose you toss a fair coin 10 times, let X denote the number of heads. (a) What is the probability that X=5? (b) What is the p
zubka84 [21]

Answer:  The required answers are

(a) 0.25,    (b) 0.62,    (c) 6.

Step-by-step explanation:  Given that we toss a fair coin 10 times and X denote the number of heads.

We are to find

(a) the probability that X=5

(b) the probability that X greater or equal than 5

(c) the minimum value of a such that P(X ≤ a) > 0.8.

We know that the probability of getting r heads out of n tosses in a toss of coin is given by the formula of binomial distribution as follows :

P(X=r)=^nC_r\left(\dfrac{1}{2}\right)^r\left(\dfrac{1}{2}\right)^{n-r}.

(a) The probability of getting 5 heads is given by

P(X=5)\\\\\\=^{10}C_5\left(\dfrac{1}{2}\right)^5\left(\dfrac{1}{2}\right)^{10-5}\\\\\\=\dfrac{10!}{5!(10-5)!}\dfrac{1}{2^{10}}\\\\\\=0.24609\\\\\sim0.25.

(b) The probability of getting 5 or more than 5 heads is

P(X\geq 5)\\\\=P(X=5)+P(X=6)+P(X=7)+P(X=8)+P(X=9)+P(X=10)\\\\=^{10}C_5\left(\dfrac{1}{2}\right)^5\left(\dfrac{1}{2}\right)^{10-5}+^{10}C_6\left(\dfrac{1}{2}\right)^6\left(\dfrac{1}{2}\right)^{10-6}+^{10}C_7\left(\dfrac{1}{2}\right)^7\left(\dfrac{1}{2}\right)^{10-7}+^{10}C_8\left(\dfrac{1}{2}\right)^8\left(\dfrac{1}{2}\right)^{10-8}+^{10}C_9\left(\dfrac{1}{2}\right)^9\left(\dfrac{1}{2}\right)^{10-9}+^{10}C_{10}\left(\dfrac{1}{2}\right)^{10}\left(\dfrac{1}{2}\right)^{10-10}\\\\\\=0.24609+0.20507+0.11718+0.04394+0.0097+0.00097\\\\=0.62295\\\\\sim 0.62.

(c) Proceeding as in parts (a) and (b), we see that

if a = 10, then

P(X\leq 0)=0.00097,\\\\P(X\leq 1)=0.01067,\\\\P(X\leq 2)=0.05461,\\\\P(X\leq 3)=0.17179,\\\\P(X\leq 4)=0.37686,\\\\P(X\leq 5)=0.62295,\\\\P(X\leq 6)=0.82802.

Therefore, the minimum value of a is 6.

Hence, all the questions are answered.

3 0
3 years ago
It has been decided that 100 people need to be surveyed to decide the publics opinion on a school building project. A student su
Morgarella [4.7K]

Answer:

The proposed way of sampling is a biased way to perform the survey.

Step-by-step explanation:

Convenience sampling is a kind of non-probability sampling method that comprises of the sample being taken from that portion of the population that is near to hand.  In this type of sampling method, all items doesn’t have an equivalent chance of being selected, which doesn’t comprises of random collection of items.

Convenience sampling is where we take in items which are easy to reach.

Convenience sampling consists of selection bias, i.e.e the bias involved in the sample due to inappropriate selection procedures.

For example, randomly selecting 4 people sitting near him to guesstimate the mean age of the class is a convenience sampling example. or gathering information on customer satisfaction by interviewing 6 randomly selected customers from a local store is an illustration of convenience sampling.

In this case, the sample suggested by the students consists of surveying the first 100 people who enter the school, about the public opinion on a school building project.

This is an example of convenience sample.

So, there is a selection bias present in the sample.

Thus, the proposed way of sampling is a biased way to perform the survey.

4 0
3 years ago
What’s the answer to this question? Me and one of my classmates are having trouble on it! ( middle school btw I put high school
elena55 [62]

Answer:

6

Step-by-step explanation:

It would be 6 because on a square, all the sides have to be the same length. The length of the square is equal to the base of the parallelogram.

5 0
2 years ago
Read 2 more answers
I'd really appreciate it if someone could help me with these square problems :/
adelina 88 [10]
I would but I don’t want to ;/
3 0
3 years ago
<img src="https://tex.z-dn.net/?f=1.%20%5Cfrac%7B1%7D%7B3%7D%20%20%2B%20%20%5Cfrac%7B3%7D%7B2%7D%20%20%2B%20%20%5Cfrac%7B6%7D%7B
kondaur [170]

Answer:

1. 3.33333333333

2. -1.3

3. 2.61904761905

4. 2.00833333333

8 0
2 years ago
Other questions:
  • Lauren paid a one - time membership fee of $70.25 when joining a gym, and since then she has been paying $36.45 per month. So fa
    5·1 answer
  • Which best explains why the equation 7×+3=7×+3 has infinitely many solutions
    8·1 answer
  • raul invests $1000 in a savings account that earns 5% interest compounded annually. how much money will he have in the account a
    9·2 answers
  • If prism A and Prism B have a ratio of similarity of 2:3, what is the volume of prism A if Prism B's volume is 56 cubic inches
    7·1 answer
  • during a soccer game Aaron scored 1 out of 2 goals attempted.Lauren scored 6 out of 8 goals attempted. write the fraction that r
    12·1 answer
  • What has a fraction in its numerator, denominator, or both
    11·1 answer
  • What is an expression equivalent to 2/3 (4x + 9)
    12·1 answer
  • What is the explicit formula for this arithmetic sequence?<br> -11, -18, -25, -32, ...
    6·1 answer
  • Find the surface area of the composite figure.
    6·1 answer
  • 16. What is the measure of ZAOB?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!