I used elimination to solve this system of equations and found out that y = 1. What does x equal?

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

Can any kind soul help me ASAP!

CaHeK987 [17]

Answer:

Hope it helps u

Step-by-step explanation:

As we know that ,

Mean = sum of the terms/ numbers of terms

But here grouped data is given so , we use the formula

Mean=∑[f. m]/ ∑f

where f is frequency and m is mid point of each height ,

Now first we have to find the mid point of each interval, where

midpoint of each interval = (lower boundary + upper boundary)/2

m1=(150+154)/2 = 152

m2=(155+159)/2= 157,now found other by same formula, for each interval

m3= 162

m4= 167

m5=172 Now we find the midpoint of each interval ,so now

∑[f. m]=f1*m1+f2*m2+f3*m3+f4*m4+f5*m5

now putting the values of each frequency for given interval and midpoint of each interval we will get,

∑[f. m]=456+942+1296+167*x+344 = 167*x+3038

Now find,

∑f=f1+f2+f3+f4+f5

∑f=19+x

Now we have,

∑[f. m]=167*x+3038

∑f=19+x

also given mean height=161.6 cm

putt these values in above equation we get,

161.6= $\frac{167*x+3038}{19+x}$

now solve this ,

161.6(19+x)=167*x+3038

3070.4+161.6*x=167*x+3038

3070.4-3038=167*x-161.6*x

32.4=5.4*x

x=32.4/5.4

3 0

3 years ago

Algebraic expressions describe a ________________. They can be as

Jobisdone [24]

Answer:

Algebraic expressions describe an algebraic operation. They can be as simple as a number, or they can include integer constants of numbers, variables, and symbols.

Step-by-step explanation:

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2 years ago

If the sales tax of a state is 8%what is the price of a $400 punching bag

Aleks [24]

The answer is $432

Multiply 400 by .08 and you get 32, which you add to the original price.

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3 years ago

Karen lives for tenth of a mile from the mall right to equivalent fractions that show what fraction of the model Karen lives fro

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4/10 is equal to 2/5

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3 years ago