4) The average IQ of adult population is 100 and are normally distributed. A researcher believes the IQ of adults is lower. A random sample of 7 adults are tested and scored: Use a significance level of 0.05. 69 , 79 , 89 , 99 , 109, 98, 81

A study was conducted to determine the proportion of people who dream in black and white instead of color. Among 309 people over the age of​ 55, 68 dream in black and​ white, and among 295 people under the age of​ 25, 15 dream in black and white. Use a 0.05 significance level to test the claim that the proportion of people over 55 who dream in black and white is greater than the proportion for those under 25.    identify the test statistic? identify the p value ? 98% confidenc interaval? reject or not to reject and why?

A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. When evaluated using the 5% level of significance, what is the decision and interpretation of the null hypothesis?  Show all steps.

40 people are randomly sent to walk one of four trails. The time (in minutes) they spend completing each trail is recorded in the table below. (a) Test to see if the times needed to complete a trail vary. Use a 0.05 significance level. (b) Test each pair (A/B, A/C, A/D, B/C, B/D, C/D) to see which trails have a statistically significant difference. Indicate your p-value for each comparison, and when the effect is statistically significant (use 0.05 as your significance level), declare which trail of the two takes more time to complete. Trail A - 30, 33, 41, 27, 36, 31, 37, 40, 29, 35 Trail B - 27, 33, 38, 41, 40, 38, 35, 44, 41, 39 Trail C - 25, 34, 41, 39, 32, 30, 36, 35, 27, 33 Trail D - 41, 39, 46, 37, 40, 42, 50, 42, 50, 33, 47, 43