The number of chocolate chips in a bag of chocolate chip cookies is approximately normally distributed with a mean of 1261 chips and a standard deviation of 118 chips. (a) Determine the 30th percentile for the number of chocolate chips in a bag. (b) Determine the number of chocolate chips in a bag that make up the middle 97% of bags. (c) What is the interquartile range of the number of chocolate chips in a bag of chocolate chip cookies? (a) The 30th percentile for the number of chocolate chips in a bag of chocolate chip cookies is chocolate chips. (Round to the nearest whole number as needed.)

A marketing researcher wants to estimate the mean amount spent per year ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of $55 and a standard deviation of $52. Complete parts (a) and (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from $51? (Use a 0.01 level of significance.) State the null and alternative hypotheses. Ho: H (Type integers or decimals. Do not round. Do not include the $ symbol in your answer.) Identify the critical value(s). The critical value(s) is/are (Type an integer or a decimal. Round to two decimal places as needed. Use a comma to separate answers as needed.) Determine the test statistic. The test statistic, 1STAT, is (Type an integer or a decimal. Round to two decimal places as needed.) State the conclusion. Ho. There is evidence that the…

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 99.3-cm and a standard deviation of 1.5-cm. For shipment, 25 steel rods are bundled together.Find P27, which is the average length separating the smallest 27% bundles from the largest 73% bundles. P27 =

a-c

A marketing researcher wants to estimate the mean amount spent per year​ ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of ​$58and a standard deviation of ​$55.Complete parts​ (a) and​ (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from ​$51​? ​(Use a 0.01 level of​ significance.)   State the null and alternative hypotheses.

Cotinine levels were measured in a group of non-smokers exposed to tobacco smoke (n =40), the mean of the sample was 60.58 ng/Ml and the standard deviation was 138.08 ng/Ml. Also, cotinine levels were measured in a group of non-smokers not exposed to tobacco smoke(n =40), the mean of the sample was 16.35 ng/mL and the standard deviation was 62.53 ng/mL. Cotinine is a metabolite of nicotine, meaning that when nicotine is absorbed by the body, cotinine is produced. Use a 0.05 significance level to test the claim that non-smokers exposed to tobacco smoke have a higher mean nicotine level than nonsmokers not exposed to tobacco smoke. a)Define the parameter and state null and alternative hypothesis b)Test Statistics c) Critical Value Approach d) Conclusion

For each day of last year, the number of vehicles passing through a certain intersection was recorded by a city engineer. One objective of this study was to determine the percentage of days that more than 425 vehicles used the intersection. If the mean data was 375 vehicles per day and the standard deviation was 25 vehicles:         (c)  Suppose the relative frequency distribution for the data is bell-shaped, then what percentage of days                    between 325 and  425 vehicles used the intersection ?

A basketball player makes 56 free throws in a season. The average number of free throws made in the league is 52, and the standard deviation is 4. A softball player makes 42 hits in a season. The average number of hits mase in the league is 38, and the standard deviation is 6. Calculate Z-scores for the two and compare them.  Which one is better at their sport?

A researcher studied 5050 adults daily screen time. She had them record the amount of hours (rounded to the nearest hour) they spent looking, listening or reading at computer or cell phone daily. The frequency table below shows the results. Hours of Screen Time Frequency 7 5 8 6 9 4 10 5 11 8 12 10 13 9 14 3 The researcher found that the mean number of hours of the data set was 10.7210.72. She wants to also find range and standard deviation. Find the range of the data set.range =    Find the standard deviation of the data setstandard deviation =   Round your result to two decimal places.

Body TemperaturesThe body temperatures (in degrees Fahrenheit) have been recorded for a sample of 130 healthy adults - 65 males and 65 females (Shoemaker, 1996). The sample mean body temperature for males is 98.394 degrees Fahrenheit, and the sample standard deviation for males is 0.743 degrees Fahrenheit. The sample mean body temperature for females is 98.105 degrees Fahrenheit, and the sample standard deviation for females is 0.699 degrees Fahrenheit. a. produce a 95% confidence interval for the population mean body temperature of a healthy male.  Round your answers to three decimal places. (___, ___) b. produce a 95% confidence interval for the population mean body temperature of a healthy female.  Round your answers to three decimal places. (___, ___) d d. Report the half-width of these two intervals.  Round to 3 decimal places. Half width for men:  ____ Half width for women:  ___