In what circumstances is the z score used instead of a t statistic for a hypothesis test?   a. given the population mean, the z score is used when the standard deviation is unknown   b. given the population mean, the z score is used when the population variance or standard deviation is known   c. given the population mean, the z score is used if you are not sure that the population distribution is normal   d. given the population mean, the z score is used when the sample size is 30 or larger

Q: Test the claim that the mean GPA of night students is larger than 3.5 at the 0.005 significance…

A: claim : The mean GPA of night students is larger than 3.5, i.e.  μ > 3.5 Hypothesis : H0 : μ ≤3.5…

Q: Test the claim that the mean GPA of night students is smaller than 3.1 at the 0.10 significance…

A:

Q: Test the claim that the mean GPA of night students is smaller than 2.5 at the .05 significance…

A:

Q: responses:     Response       Yes: 25       No: 55 Test the hypothesis: H0: in the population 1/3…

A:

Q: Test the claim that the mean GPA of night students is significantly different than 2.4 at the 0.02…

A:

Q: Test the claim that the mean GPA of night students is significantly different than 2.4 at the 0.2…

A: Given data : sample size, n = 40 sample mean, x̄ = 2.37 sample standard…

Q: If you are conducting a hypothesis test of a single population mean, and you do not know the…

A: If you are conducting a hypothesis test of a single population mean, and you do not know the…

Q: When using a hypothesis test for two means and you do NOT have the population standard deviation, it…

A: The distribution used for the hypothesis test for two means are t and z.

Q: Consider the following hypothesis test: H0: µ  50 and Ha: µ > 50. A sample of 60 provided a sample…

A: Solution we have given that A sample of 60 provided a sample mean of 51.8. The population standard…

Q: Independent random samples from normal populations produced the results shown in the table to the…

A: Given n1=5 n2=4

Q: Test the claim that the mean GPA of night students is significantly different than 3.1 at the 0.02…

A: Solution

Q: Casey is a statistics student who is conducting a one-sample z‑test for a population proportion p…

A: Casey is a statistics student who is conducting a one-sample z‑test for a population proportion p…

Q: We are interested in significant differences (level a = 0.05) between the expected values µ1 and µ2…

A: In order to test significant differences between the expected values μ1 and μ2 of two populations.…

Q: If all other factors are held constant, which of the following results in a decrease in the…

A: The true parameter is closer to the value of the null hypothesis. If the true parameter is closer to…

Q: If all other factors are held constant, which of the following results in an increase in the…

A:

Q: "A student believes they have stumbled upon a new unique way to study, and believes it will boost…

A: Solution. Given the researcher wants to compare the small group of her friends use the method before…

Q: Part 1 of 4 Victoria, an accomplished marathon runner, claims that the standard deviation for her…

A: Given: n=11 The samples are: 227.2, 233.3, 259.7, 265.8, 252.1, 228.8, 222.6, 202.9, 214.5, 237.2,…

Q: If all other factors are held constant, which of the following results in a decrease in the…

A: Power = 1 - P(Type II error) the true parameter is closer to the value of the null hypothesis.,…

Q: Consider a problem with the following hypothesis test at the 5% level of significance: H: u = 4, H :…

A: Given: μ=4σ=0.08n=25x¯=4.01 Hypothesis: H0: μ=4H1: μ>4

Q: If the critical z-value for a hypothesis test equals 2.45, what value of the test statistic would…

A: If the critical z value for a hypothesis test equals 2.45, The value of the test statistic that…

Q: A car leasing firm's records indicate that the mean number of miles driven annually in its cars has…

A: GivenA car leasing firm's records indicate that the mean number of miles drivenannually in its cars…

Q: Test the claim that the proportion of people who own cats is significantly different than 50% at the…

A: Population proportion = p₀ = 0.5 Sample proportion = p̂ = 0.43

Q: Reynaldo is conducting a one-sample z‑test of the null hypothesis H0:p=0.64 against the alternative…

A: The z test is used to determine the mean significance between the sample and the population. It is…

Q: Test the claim that the mean GPA of night students is larger than 3.1 at the .10 significance level.…

A:

Q: Which of the following are FALSE statements? 1. If there is sufficient evidence to reject a null…

A: Q1) A . I & II only first statement is false The p-values is affected by the sample size. Larger…

Q: Calculate the ?-value of the test of the following hypothesis given that the sample proportion ? =…

A: Given,sample size(n)=800sample proportion(p^)=0.63H0:P=0.60H1:P>0.60α=0.05

Q: Part 1 of 4 Victoria, an accomplished marathon runner, claims that the standard deviation for her…

A: We have to test that if the standard deviation of run time for a marathon runner is less than 17.5…

Q: D. When the sample size is sufficiently large. 7. In the estimation of a parameter using the…

A: We have given that the statements about to the t-distribution. Here, need to find the correct choice…

Q: Test the claim that the mean GPA of night students is smaller than 2.7 at the 0.10 significance…

A: From the given information, The provided information as given below: Sample size (n) = 80…

Q: For a random sample drawn from a population, which of the following statement is TRUE? a) If the…

A: Let X1, X2,..., Xn be the random sample taken from the population of mean μ and variance σ2. Then,…

Q: If all other factors are held constant, which of the following results in an increase in the…

A: Type II error: The type II error occurs when the null hypothesis can be accepted if it is false. It…

Q: Aurora is conducting a one-sample ?z test of the null hypothesis ?0:?=0.12H0:p=0.12 against the…

A:

Q: Can the null hypothesis be rejected at the; i. 0.01 level of significance?​​​​​​ ii. 0.05 level of…

A: To decide whether the null hypothesisbis rejected or not, we compare p-value and level of…

Q: find: i. 98% confidence interval for the ratio of the variances.

A:

Q: 6. "In statistical inference for proportions, standard error (SE) is calculated differently for…

A: In statistical inference for proportion, standard error (SE) is calculated differently for…

Q: sociologist wants to study what proportion of people have significant relationship problems due to…

A: The formula for z score in proportion test is, Z=p^-pp(1-p)n The sample proportion is,  p^=xn p is…

Q: Part 1 of 4 Victoria, an accomplished marathon runner, claims that the standard deviation for her…

A: Given that Victoria looks up 11 of her race times (in minutes). Therefore the sample size n=11.

Q: Assume we are given the below details to test if population A has a larger variance than population…

A: The variance of population A is is σ12 and the variance of population B is σ22.

Q: If all other factors are held constant, which of the following results in a decrease in the…

A:

Q: State the null and alternative hypotheses for the situation described below for a statistical test.…

A: Different null and alternative hypotheses can be defined as given below Two tailed test:  Left tail…

Q: (i)The interquartile range of a sample is influenced by extreme values. (ii)A sampling distribution…

A: According to the answering guidelines, we can answer only three subparts of a question and the rest…

Q: Consider the following statements:  I. As far as the probability of a Type I error is concerned, a…

A: Given; The objective is to find whether the give two statements are true are false

Q: Test the claim that the mean GPA of night students is smaller than 2.1 at the 0.025 significance…

A:

Q: When testing for differences between the means of two related populations, what is the null…

A:

Q: Which of the following statements below is incorrect about Type II error? The larger the effect…

A: Here, to check whether the given statements about the type II error are correct or incorrect.

Q: Use the given problem to answer the following questions: A random sample of 25 is selected from a…

A:

Q: In testing hypotheses, which of the following provides strong evidence against the null hypothesis?…

A:

Q: Test the claim that the mean GPA of night students is significantly different than 3.5 at the 0.05…

A: Given, Sample size = 50 Sample mean = 3.48 Population standard deviation = 0.07   Set up the null…

Q: Test the claim that the mean GPA of night students is smaller than 2.7 at the 0.10 significance…

A:

Q: In performing a hypothesis test where the null hypothesis is that the population mean is 4.8 against…

A: Given information: The null and the alternative hypothesis are: H0 : μ=4.8Ha : μ≠4.8 A random sample…