7.- A random sample of 50 consumers taste-tested a heW ShaCk (0: do not like; 1: like; 2: indifferent) and recorded as follows: 10012011000102022001100001020001001001010200110001 Options Frequency table results for varl: Count- 50 varl. Frequency Relative Frequency O.58 lo 15 03 0.12 a) Use an 80% confidence interval to estimate the proportion of consumers who like the snack food. b) Test Ho: p = 0.50 against Ha: p > 0.50, where p is the proportion of customers who do nột like the snack food. Use a = 0.10. Answer: CV = RR = Test statistics = P-value =

3. The average (or mean) amount of hours spent on social media per day is 2 hours and the standard deviation is 2 hours. Calculate the z scores for the following individual scores: Person 1 (X) = 1 hour, z = Person 2 (X) = 3 hours, z= Person 3 (X) = 4 hours, z=

The brain volumes (cm³) of 20 brains have a mean of 1113.7 cm³ and a standard deviation of 128.9 cm³. Use the give standard deviation and the range rule of thumb to identify the limits separating values that are significantly low or significantly high. For such data, would a brain volume of 1361.5 cm³ be significantly high? 3 Significantly low values are cm³ or lower. (Type an integer or a decimal. Do not round.)

2.) A researcher is interested in the number of words four-year-old children understand in an unfamiliar accent. On average four-year-olds understand an average of μ = 1,500 words with a standard deviation of o = 72 words. A random sample of n-64 four-year-olds complete a study identifying objects labeled in an unfamiliar accent. The sample had a mean score of M = 1485. Does accented speech influence a child's understanding? Test at the a=.05 level. a.) Step 1: State the Hypotheses Ho: H₁: b.) Step 2: Determine the critical region and draw it on the distribution above: Zritical- c.) Step 3: Calculate the test statistics (here: a z-test). Zobserved = d.) Step 4: Make a decision. Circle one: Reject Null (Ho) or Fail to Reject Null (Ho) e.) State your conclusions about the research scenario in sentence form: f.) What is the estimated effect size (Cohen's d) in this study? Do you characterize it as being small, medium or large? d=

2. A principal of high school was concerned with amount of time her students devote to working at after-school jobs. She randomly selected 25 students, obtained their working hours for 1 week and computed x = 12.5 hours and s = 4.5 hours. She claims that her students work significantly more than the mean of 10.7 hours from a study conducted by the National Association of State High School Association. Test her claim by using the 5% level of significance.

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The lengths of pregnancies in a small rural village are normally distributed with a mean of 269 days and a standard deviation of 16 days. a) In what range would you expect to find the middle 68% of most pregnancies? Between and b) If you were to draw samples of size 38 from this population, in what range would you expect to find the middle 68% of most averages for the lengths of pregnancies in the sample? Between and Enter your answers as numbers. Your answers should be accurate to one decimal places. Submit Question ロI & #3 2$ 6 7 8. 2 3 4 y e d f h づ