Question 18 25

The CEO of the Jen and Benny's ice cream company is concerned about the net weight of ice cream in their 50 ounce ice cream tubs

MissTica

Answer:

$t=\frac{54.98-52}{\frac{8.43}{\sqrt{26}}}=1.8025$

We need to find the degrees of freedom given by:

$df = n-1= 26-1 = 25$

Since is a right tailed test the p value would be:

$p_v =P(t_{25}>1.8025)=0.0418$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the average is higher than 52 at 5% of signficance.

Step-by-step explanation:

Data given and notation

$\bar X=54.98$ represent the sample mean

$s=8.43$ represent the sample deviation

$n=26$ sample size

$\mu_o =52$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is higher than 52, the system of hypothesis would be:

Null hypothesis: $\mu \leq 52$

Alternative hypothesis: $\mu > 52$

Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

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

$t=\frac{54.98-52}{\frac{8.43}{\sqrt{26}}}=1.8025$

P-value

We need to find the degrees of freedom given by:

$df = n-1= 26-1 = 25$

Since is a right tailed test the p value would be:

$p_v =P(t_{25}>1.8025)=0.0418$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the average is higher than 52 at 5% of signficance.

7 0

3 years ago

Read 2 more answers

In spring 2014, faculty from the City University of New York (CUNY) reported on a randomized controlled trial they conducted. Th

Lady_Fox [76]

Answer:

A) explanatory variable is "The extra support given by faculties"

B) the response variable is;

"How successful students who were placed directly into college - level statistics were able to outperform both elementary algebra treatment groups."

C) Confounding Variable is "ability of students to be successful or pass"

D) Experiment

Step-by-step explanation:

A) An explanatory variable is simply a type of independent variable used to explain the changes that occur in another variable. Furthermore, it can be manipulated by the researcher and is also used to predict differences in the response variable.

Now, from the question, we see that the variable "extra support by the faculties" is used to determine how successful community college students who were placed directly into college - level statistics were in outperforming both elementary algebra treatment groups.

Thus, the explanatory variable is "The extra support given by faculties"

B) In answer A above, we saw that the explanatory variable is used to predict the response variable.

We saw that the explanatory variable predicted how successful community college students who were placed directly into college - level statistics were in outperforming both elementary algebra treatment groups.

Thus, the response variable is;

"How successful students who were placed directly into college - level statistics were able to outperform both elementary algebra treatment groups."

C) A confounding variable is one that influences or changes the effect of the dependent & independent variable. It is therefore used to influence the result/outcome of an experiment/research.

From the question, it's clear that the ability of the students to pass or be successful is what influences the effect of the support by the faculties.

Thus, the Confounding Variable is "ability of students to be successful or pass"

D) The question portrays an experiment because it is being used to check if an hypothesis statement is true or false.

3 0

3 years ago

Find the missing side length and round it to the nearest tenth please :)

Alchen [17]

Answer:

171

Step-by-step explanation:

This is a Right triangle,

So this means that all the sides should add up to 180,

So far we have 9

So we will have to Subtract 9 from 180 which leaves us with 171,

I hope this is correct!!

7 0

3 years ago

The mean time it takes to walk to the bus stop is 8 minutes (with a standard deviation of 2 minutes) and the mean time it takes

11111nata11111 [884]

(a) Average time to get to school
Average time (minutes) = Summation of the two means = mean time to walk to bus stop + mean time for the bust to get to school = 8+20 = 28 minutes

(b) Standard deviation of the whole trip to school
Standard deviation for the whole trip = Sqrt (Summation of variances)

Variance = Standard deviation ^2
Therefore,
Standard deviation for the whole trip = Sqrt (2^2+4^2) = Sqrt (20) = 4.47 minutes

(c) Probability that it will take more than 30 minutes to get to school
P(x>30) = 1-P(x=30)
Z(x=30) = (mean-30)/SD = (28-30)/4.47 ≈ -0.45
Now, P(x=30) = P(Z=-0.45) = 0.3264
Therefore,
P(X>30) = 1-P(X=30) = 1-0.3264 = 0.6736 = 67.36%

With actual average time to walk to the bus stop being 10 minutes;

(d) Average time to get to school
Actual average time to get to school = 10+20 = 30 minutes

(e) Standard deviation to get to school
Actual standard deviation = Previous standard deviation = 4.47 minutes. This is due to the fact that there are no changes with individual standard deviations.

(f) Probability that it will take more than 30 minutes to get to school
Z(x=30) = (mean - 30)/Sd = (30-30)/4.47 = 0/4.47 = 0

From Z table, P(x=30) = 0.5
And therefore, P(x>30) = 1- P(X=30) = 1- P(Z=0.0) = 1-0.5 = 0.5 = 50%

8 0

3 years ago

Which statements are true about the rules of multiplication for signed numbers? Check all that apply.

Mekhanik [1.2K]

Answer:

i think that 1, 3 and 4 are correct !!

Step-by-step explanation:

youre welcome, have a nice day!

NOTE: next time please provide the list of choices so it can be easier to help you

4 0

4 years ago