Rita recorded the number of cyclists on a Saturday for 4 weeks. The results for the first 3 weeks are shown in the table.

A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies. Random

Yuliya22 [10]

Answer:

b) independent samples t-test

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

$p_v =2*P(t_{8}>0.154) =0.881$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 (boys) is NOT significantly different than the mean for the group 2 (Girls).

Step-by-step explanation:

The system of hypothesis on this case are:

Null hypothesis: $\mu_1 = \mu_2$

Alternative hypothesis: $\mu_1 \neq \mu_2$

Or equivalently:

Null hypothesis: $\mu_1 - \mu_2 = 0$

Alternative hypothesis: $\mu_1 -\mu_2\neq 0$

Our notation on this case :

$n_1 =5$ represent the sample size for group 1

$n_2 =5$ represent the sample size for group 2

We can calculate the mean and deviation for eaach group with the following formulas:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$s = \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X_1 =5.92$ represent the sample mean for the group 1

$\bar X_2 =5.74$ represent the sample mean for the group 2

$s_1=1.88$ represent the sample standard deviation for group 1

$s_2=1.81$ represent the sample standard deviation for group 2

If we see the alternative hypothesis we see that we are conducting a bilateral test and with independnet samples t test.

b) independent samples t-test

The statistic is given by this formula:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{\sqrt{\frac{s^2_1}{n_1}}+\frac{S^2_2}{n_2}}$

And now we can calculate the statistic:

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

The degrees of freedom are given by:

$df=5+5-2=8$

And now we can calculate the p value using the altenative hypothesis:

$p_v =2*P(t_{8}>0.154) =0.881$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 (boys) is NOT significantly different than the mean for the group 2 (Girls).

7 0

4 years ago

These spam comments are seriously getting out of hand and are really annoying. And the worst part is that you can’t really do an

RideAnS [48]

Answer: Yea at least brainly deleting them when they catch them

Step-by-step explanation:

7 0

3 years ago

What would your salary each year be if you earned $5,000 per week?

choli [55]

Yearly salary would be 240,000 for 5,000 and 48,000 for 1,000 a week

8 0

3 years ago

50 POINTS !! PLEASE HELP !! ILL GIVE BRAINLIEST TO THE RIGHT ANSWERS.

maks197457 [2]

Answer:

16

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Multiplication Property of Equality
Division Property of Equality
Addition Property of Equality
Subtraction Property of Equality

Trigonometry

[Right Triangles Only] Pythagorean Theorem: a² + b² = c²

a is a leg
b is another leg
c is the hypotenuse

Step-by-step explanation:

Step 1: Define

Identify variables

Leg a = a

Leg b = 12

Hypotenuse c = 20

Step 2: Solve for a

Substitute in variables [Pythagorean Theorem]: a² + 12² = 20²
Evaluate exponents: a² + 144 = 400
[Subtraction Property of Equality] Isolate a term: a² = 256
[Equality Property] Square root both sides: a = 16

3 0

3 years ago

Read 2 more answers

You have been saving nickels, dimes, and quarters in a jar for about a year. You decide to see how much money you've saved up. W

anyanavicka [17]

Answer:

x = number of nickels = 127

y = number of dimes = 156

z = number of quarters = 78

Step-by-step explanation:

Let

x = number of nickels

y = number of dimes

z = number of quarters

Total worth of the coins = $41.45

Total number of coins = 361

x + y + z = 361 (1)

dime = $0.1,

nickel = $0.05

quarter = $0.25

0.05x + 0.1y + 0.25z = 41.45 (2)

twice as many dimes as quarters.

y = 2z

Substitute y = 2z into (1) and (2)

x + 2z + z = 361

0.05x + 0.1(2z) + 0.25z = 41.45

x + 3z = 361

0.05x + 0.2z + 0.25z = 41.45

x + 3z = 361 (3)

0.05x + 0.45z = 41.45 (4)

Multiply (4) by 20

x + 3z = 361 (3)

x + 9z = 829 (5)

Subtract (3) from (5)

9z - 3z = 829 - 361

6z = 468

Divide both sides by 6

z = 468 / 6

= 78

z= 78

Recall,

y = 2z

= 2(78)

= 156

y = 156

Substitute the value of y and z into

x + y + z = 361

x + 156 + 78 = 361

x + 234 = 361

x = 361 - 234

= 127

x= 127

x = number of nickels = 127

y = number of dimes = 156

z = number of quarters = 78

6 0

3 years ago