Use this information for questions 6 & 7.

By the time children are 2 years old, they can say about 50 words. A child development researcher believes that babies who regularly have more than 4 hours of one-to-one interaction with an adult daily will have larger vocabularies.She thenobserves 15 such toddlers and determines they can say the following number of words:

70 61 54 48 58 83 77 80 78 66 59 52 57 61 49

1.) Construct a stemplot to confirm the data is mound-shaped so that t-procedures can be used. Then construct a 97% confidence interval to estimate the average number of words for two-year-olds who have more than 4 hours of one-to-one interaction with an adult.

Select all correct representations.

a.)63.5 + 14.4

b.(57.1, 70.0)

c.)56.3 < <70.7

d.(57.1, 69.9)

e.)63.5 + 6.5

f.)63.5 + 7.2

g.(56.3, 70.7)

7.) Use the interval you found in the previous question to test the hypothesis that 2 year olds who've regularly had the adult interaction described do not say 50 words on average. H₀: ==50

H_a: 50

What is the correct conclusion? Select all correct interpretations.

a.There IS evidence at the =0.03 level that the average number of words spoken by 2 year olds who've regularly had the adult interaction described do not say 50 words because 50 is not in the interval.

b.There is evidence at the=0.03 level that the average number of words spoken by 2 year olds who've regularly had the adult interaction described is about 63.5

c.The researcher should reject the null hypothesis.

d.The researcher should accept the null hypothesis.

e.There is NO evidence at the =0.03 level that the average number of words spoken by 2 year olds who've regularly had the adult interaction described do not say 50 words because 50 is not in the interval