Please help, tysm if you do :D

kakasveta [241]

1. Below
2. Above
3. Sea Level

3 0

3 years ago

A random sample of 49 measurements from one population had a sample mean of 15, with sample standard deviation 5. An independent

kotykmax [81]

Answer:

Comparing the p value with the significance level $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the difference between the two groups is significantly different.

Step-by-step explanation:

$\bar X_{1}=15$ represent the mean for sample 1

$\bar X_{2}=18$ represent the mean for sample 2

$s_{1}=5$ represent the sample standard deviation for 1

$s_{f}=6$ represent the sample standard deviation for 2

$n_{1}=49$ sample size for the group 2

$n_{2}=64$ sample size for the group 2

$\alpha=0.01$ Significance level provided

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the difference in the population means, the system of hypothesis would be:

Null hypothesis: $\mu_{1}-\mu_{2}=0$

Alternative hypothesis: $\mu_{1} - \mu_{2}\neq 0$

We don't have the population standard deviation's, so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}}$ (1)

And the degrees of freedom are given by $df=n_1 +n_2 -2=49+64-2=111$

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

With the info given we can replace in formula (1) like this:

$t=\frac{(15-18)-0}{\sqrt{\frac{5^2}{49}+\frac{6^2}{64}}}}=-2.897$

P value

Since is a bilateral test the p value would be:

$p_v =2*P(t_{111}$

Comparing the p value with the significance level $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the difference between the two groups is significantly different.

7 0

3 years ago

How are Ratios,rates and unit rates used to solve problems?

insens350 [35]

Answer:

hope u understand

Step-by-step explanation:

Unit rates can conveniently be multiplied by any desired number in order to answer questions about differently scaled questions. E.g. If three marbles cost 30 cents, how much will eleven marbles cost?

A unit rate is a ratio such as 30 cents : 3 marbles = 10 cents per (1) marble, after doing the division.

6 0

3 years ago

Read 2 more answers

Last year Tyler used 60 feet of fencing to enclose a rectangular garden with an area of 200 ft². This year Tyler plans to use 12

Alik [6]

Answer:

Area of new garden = 800 ft²

Step-by-step explanation:

Given:

Old fencing = Parameter of old garden = 60 ft

Area of old garden = 200 ft

Find:

Area of new garden if Parameter of new garden is 120 ft

Computation:

Assume;

Length of old garden = l

Width of old garden = b

So,

2[l + b] = 60

l + b = 30

l = 30 - b

Area of old garden = 200 ft

l x b = 200

So,

(30 - b)b = 200

b² - 30b + 200 = 0

b² - 20b - 10b + 200

b(b-20) - 10(b-20)

(b-20)(b-10)

So,

Width of old garden = 10 ft

Length of old garden = 20 ft

New parameter is double

So,

Width of new garden = 10 x 2 = 20 feet

Length of old garden = 20 x 2 = 40 feet

Area of new garden = l x b

Area of new garden = 20 x 40

Area of new garden = 800 ft²

4 0

3 years ago

An ice skater standing on an icy surface pushes off a wall. The ice skater has a mass of 60 kg and exerts a force of 100 N on th

dexar [7]

It's 100 N, which follows directly from Newton's third law - for every force acting on a body, that same body exerts a force equal in magnitude in response.

8 0

3 years ago