Question

A graduate student conducted an experiment in which 23 ​ten-month-old babies were asked to watch a climber character attempt to ascend a hill. On two​ occasions, the baby witnesses the character fail to make the climb. On the third​ attempt, the baby witnesses either a helper toy push the character up the hill or a hinderer toy prevent the character from making the ascent. The helper and hinderer toys were shown to each baby in a random fashion for a fixed amount of time. The baby was then placed in front of each toy and allowed to choose which toy he or she wished to play with. In 20 of the 23 ​cases, the baby chose the helper toy. Complete parts ​(a) through ​(d) below. ​(a) Why is it important to randomly expose the baby to the helper or hinderer toy​ first? A. The randomness in the order of exposure is important to satisfy the conditions of using the binomial probability distribution. B. The randomness in the order of exposure is important to make sure half the babies see the helper first and the other half see the hinderer first. C. The randomness in the order of exposure is important to avoid bias. D. The randomness in the order of exposure is important to minimize the effect of the sample standard deviation. ​(b) What would be the appropriate null and alternative hypotheses if the researcher is attempting to show that babies prefer helpers over​ hinderers? Upper H 0​: p ▼ equals not equals greater than less than 0.5 Upper H 1​: p ▼ equals greater than not equals less than 0.5 ​(c) Use the binomial probability formula to determine the​ P-value for this test. ​P-valueequals nothing ​(Round to three decimal places as​ needed.) What is the correct conclusion regarding the null​ hypothesis? A. Do not reject Upper H 0. Although no level of significance is​ given, there is insufficient evidence to suggest the proportion of babies who choose the helper toy is greater than 0.5. B. Do not reject Upper H 0. Although no level of significance is​ given, there is sufficient evidence to suggest the proportion of babies who choose the helper toy is greater than 0.5. C. Reject Upper H 0. Although no level of significance is​ given, there is sufficient evidence to suggest the proportion of babies who choose the helper toy is greater than 0.5. D. Reject Upper H 0. Although no level of significance is​ given, there is insufficient evidence to suggest the proportion of babies who choose the helper toy is greater than 0.5. ​(d) In testing 13 ​six-month-old babies, all 13 preferred the helper toy. The​ P-value was reported as 0.0001. Interpret this result. Choose the correct answer below. A. If the population proportion of babies who choose the helper is​ 0.5, a sample where all 13 babies choose the helper will occur in about 1 out of​ 10,000 samples of 13 babies. B. If the population proportion of babies who choose the helper is​ 0.5, a sample where all 13 babies choose the helper will occur in about 13 out of 1000 samples of 13 babies. C. If the population proportion of babies who choose the helper is​ 0.5, a sample where all 13 babies choose the helper will occur in exactly 13 out of 1000 samples of 13 babies. D. If the population proportion of babies who choose the helper is​ 0.5, a sample where all 13 babies choose the helper will occur in exactly 1 out of​ 10,000 samples of 13 babies.

Answer 1