2 + − 1 ( − ) + 7 ( 2 − )

A group of 8 children go on a field trip. Mrs. Smith is the mother of 3 of these children. School officials later announce that

Crank

Answer:

a. 0.107

b. 0.535

c. 0.642

d. 0.4

e. 0.25

f. 0.063

Step-by-step explanation:

Please see attachment

5 0

4 years ago

Read 2 more answers

Anyone know the answer ?!? Let me know please !!!

Andru [333]

Answer:

25/35 = .71 = 71%

Step-by-step explanation:

3 0

3 years ago

Four brands of lightbulbs are being considered for use in the final assembly area of the Ford F-150 truck plant in Dearborn, Mic

nlexa [21]

Answer:

Decison region :

Reject H0 : if χ² > 6.251

12.229

Step-by-step explanation:

Given :

Manufacturer A B C D

Unacceptable 29 17 9 22

Acceptable 171 183 191 178

Total 200 200 200 200

H0: There is no relationship between quality and manufacturer.

H1: There is a relationship.

Testing using the goodness of fit :

Chisquare = (observed - Expected)² / Expected

Expected Values:

19.25 19.25 19.25 19.25

180.75 180.75 180.75 180.75

Chi-Squared Values:

4.93831 0.262987 5.45779 0.392857

0.525934 0.0280083 0.581259 0.0418396

χ² = 4.93831 + 0.262987 + 5.45779 + 0.392857

+ 0.525934 + 0.0280083 + 0.581259 + 0.0418396 = 12.229

Degree of freedom, df = (4-1)(2-1) = 3*1= 3

The critical value,

χ² at 0.10, 3 = 6.251

Decison region :

Reject H0 : if χ² > 6.251

Reject H0 : 12.229 > 6.251

6 0

3 years ago

A chameleon is looking for prey. Let positive numbers represent the elevation of prey above the chameleon and

zavuch27 [327]

A. The elevation of the fly swimming

6 0

3 years ago

An advertising executive claims that there is a difference in the mean household income for credit cardholders of Visa Gold and

Maslowich

Answer:

Null hypothesis: $\mu_{Visa}=\mu_{Mastercard}$

Alternative hypothesis: $\mu_{Visa} \neq \mu_{Mastercard}$

$t=\frac{66970-59060}{\sqrt{\frac{9500^2}{11}+\frac{10000^2}{17}}}}=2.108$

$p_v =2*P(t_{26}>2.108)=0.0448$

Comparing the p value with the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we can reject the null hypothesis, and a would be a significant difference between the in the mean household income for credit cardholders of Visa Gold and of MasterCard Gold at 10% of significance .

Step-by-step explanation:

Data given and notation

$\bar X_{Visa}=66970$ represent the mean for Visa

$\bar X_{Mastercard}=59060$ represent the mean for the sample Mastercard

$s_{Visa}=9500$ represent the population standard deviation for Visa

$s_{Mastercard}=10000$ represent the population standard deviation for Mastercard

$n_{Visa}=11$ sample size for the group Visa

$n_{Mastercard}=17$ sample size for the group Mastercard

t would represent the statistic (variable of interest)

$\alpha=0.1$ significance level provided

Develop the null and alternative hypotheses for this study?

We need to conduct a hypothesis in order to check if the means for the two groups are different, the system of hypothesis would be:

Null hypothesis: $\mu_{Visa}=\mu_{Mastercard}$

Alternative hypothesis: $\mu_{Visa} \neq \mu_{Mastercard}$

Since we don't know the population deviations for each group, for this case is better apply a t test to compare means, and the statistic is given by:

$z=\frac{\bar X_{Visa}-\bar X_{Masterdcard}}{\sqrt{\frac{s^2_{Visa}}{n_{Visa}}+\frac{s^2_{Mastercard}}{n_{Mastercard}}}}$ (1)

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.

Calculate the value of the test statistic for this hypothesis testing.

Since we have all the values we can replace in formula (1) like this:

$t=\frac{66970-59060}{\sqrt{\frac{9500^2}{11}+\frac{10000^2}{17}}}}=2.108$

What is the p-value for this hypothesis test?

First we need to calculate the degrees of freedom given by:

$df= n_{Visa}+n_{Mastercard}-2 = 11+17-2= 26$

Since is a bilateral test the p value would be:

$p_v =2*P(t_{26}>2.108)=0.0448$

Based on the p-value, what is your conclusion?

Comparing the p value with the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we can reject the null hypothesis, and a would be a significant difference between the in the mean household income for credit cardholders of Visa Gold and of MasterCard Gold at 10% of significance .

4 0

3 years ago