In a study examining the effects of alcohol on reaction time it was found that even moderate alcohol consumption significantly slowed the response time to an emergency situation in a driving simulation. In a similar study researchers measured reaction times 30 minutes after each participant consumed 6 ounces of wine. Again they used a standardized driving simulation task for which the regular population averages u=400 msec. The distribution of reaction times is approximately normal with 0= 40. Assume that the researcher obtained a sample mean of M= 422 for the n=25 participants in the study.

Are the data sufficient to conclude that the alcohol has a significant effect on reaction times? Use a two tailed test with o = .01.

For this sample the standard error is ______, and the value of the z score is _____. with o=.01 the boundaries of the critical region are _____. Therefore the date _____sufficient to conclude that alcohol has a significant effect on reaction time.

Do the data provide evidence that the alcohol signifiant increased (slowed) reaction time?use a one tailed test with o= .05

The date ____provide evidence that alcohol significant increased (slowed) reaction times as the value of the z-score is _____the boundary of the critical region ____of obtained using one tailed test with o=.05

Compute cohens d to estimate the size of the effect.
Cohens d=_____

Solution Summary

The solution contains all the calculations pertaining to a hypothesis test, including test statistic and Cohen's d. Attached in Word.

18. A sample of n=16 individuals is selected from a normal population with a mean of µ=48 and a standard deviation of ±=12. After receiving a treatment, the sample mean is found to be M = 52.
a. Compare Cohen's d to evaluate the size of the treatment effect.
b. If the sample size were n = 36, what value would be obtaine

8.22. Calculate the 95% confidence interval for the following fictional data regarding daily TV viewing habits: µ = 4.7; σ = 1.3 hours; sample of 78 people with a mean of 4.1 hours.
8.30. For each of the following d values, identify the size of the effect using Cohen's guidelines. (a) d = 0.79 (b) d = - 0.43 (c) d = 0

A two tailed hypothesistest is being uses to evaluate a treatment effect with o= .05. if the sample data produce a z- score of z= -2.24 what is the correct decision?
* reject the null hypothesis and conclude that the treatment has an effect
* fail to reject the null hypothesis and conclude that the treatment has no effect

2. For each of the following, indicate whether the factor influences the numerator or denominator of the z score and determine whether the effect would be to increase the value of z (further from zero) or decrease the value of z (closer to zero). In each case, assume that all other components of the z score remain constant.
a

Many animals, including humans, tend to avoid direct eye contact and even patterns that look like eyes. Some insects, including moths, have evolved eye-spot patterns on their wings to help ward off predators. Scaife (1976) reports a study examining how eye-spot patterns affect the behavior of birds. In the study, the birds were

1. One sample has SS= 35 and the second sample has SS=45.
a) assume that n=6 for both, calculate the sample variance, and the pooled variance.
b) assume that n=6 for one and n=16 for the other, calculate the two sample variances and the pooled variance.
2. A sample of n=10 people receive medication with pain tolerance and

2. The value of the z-score in a hypothesistest is influenced by a variety of factors. Assuming that all other variables are held constant, explain how the value of z is influenced by each of the following.
a. Increasing the difference between the sample mean and the original population mean.
b. Increasing the population

A researcher is studying nonverbal intelligence in elementary school students identified as having Asperger's syndrome (an autism spectrum disorder often characterized by higher verbal communication skills than individual's with autism). Specifically, the researcher wants to study whether students identified as having Asperger'

1. A researcher recorded the amount of time each bird spent in the plain chamber during a 60-minute session. Suppose the study produced a mean of M=37 minutes on the plain chamber with SS=288 for a sample of n=9 birds. (Note: If the eye spots have no effect, then the birds should spend an average of µ=30 minutes in each chamber